Metal plate for deposition mask, and deposition mask and manufacturing method therefor

ABSTRACT

A metal plate to be used in the manufacture of a deposition mask comprises: a base metal plate; and a surface layer disposed on the base metal plate, wherein the surface layer includes elements different from those of the base metal plate, or has a composition ratio different from that of the base metal plate, and an etching rate of the base metal plate is greater than the etching rate of the surface layer. An embodiment includes a manufacturing method for a deposition mask having an etching factor greater than or equal to 2.5. The deposition mask of the embodiment includes a deposition pattern region and a non-deposition region, the deposition pattern region includes a plurality of through-holes, the deposition pattern region is divided into an effective region, a peripheral region, and a non-effective region, and through-holes can be formed in the effective region and the peripheral region.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This application is a Continuation of U.S. application Ser. No.17/574,128 filed Jan. 12, 2022, which is a Continuation of U.S.application Ser. No. 16/832,282 filed Mar. 27, 2020, which is aContinuation of U.S. application Ser. No. 16/332,910 filed Mar. 13, 2019(now U.S. Pat. No. 10,727,409), which is a U.S. National StageApplication under 35 U.S.C. § 371 of PCT Application No.PCT/KR2017/009110, filed Aug. 22, 2017, which claims priority to KoreanPatent Application No. 10-2016-0118389, filed Sep. 13, 2016 and KoreanPatent Application No. 10-2017-0014643, filed Feb. 1, 2017, whose entiredisclosures are hereby incorporated by reference.

TECHNICAL FIELD

An embodiment relates to a metal plate. Specifically, an embodimentrelates to a metal plate capable of being used for a deposition mask.More specifically, an organic light emitting diode (OLED) panel may bemanufactured by using the deposition mask according to an embodiment.

BACKGROUND ART

As a display device having high definition and low power consumption isrequired, various display devices such as a liquid crystal displaydevice and an electroluminescent display device have been developed.

The electroluminescent display device has been spotlighted as a nextgeneration display device due to excellent characteristics such as lowlight emission, low power consumption, and high definition, and thelike, as compared with the liquid crystal display device.

There are an organic light emitting display device and an inorganiclight emitting display device in an electric field display device. Thatis, an electric field display device may be classified into the organiclight emitting display device and the inorganic light emitting displaydevice according to a material of a light emitting layer.

Of these, the organic light emitting display device has receivedattention because the organic light emitting display device has a wideviewing angle, has a fast response speed, and is required to have lowpower consumption.

An organic material constituting such a light emitting layer may beformed to have a pattern for forming a pixel on a substrate by a finemetal mask method.

At this point, the fine metal mask, that is, a mask for deposition mayhave a through-hole corresponding to the pattern to be formed on thesubstrate, and, patterns of red (R), green (G), and blue (B) forming apixel may be formed by depositing the organic material after the finemetal mask is aligned on the substrate.

Recently, a display device with ultra high definition (UHD) is requiredin various electronic devices such as virtual reality (VR) devices.Accordingly, a fine metal mask having fine sized through-holes capableof forming a pattern of UHD class is required.

A plurality of through-holes may be formed at a metal plate capable ofbeing used as a deposition mask by an etching process.

At this point, when the plurality of through-holes are not uniform,uniformity of the deposition may be deteriorated, and as depositionefficiency of a pattern which is formed by the same, may bedeteriorated, process efficiency may be deteriorated

Meanwhile, it is difficult to uniformly form a fine sized through-holecapable of forming a pattern of HD or UHD class.

Alternatively, even though a fine sized through-hole is formed, adjacentthrough-holes are connected to each other, so that a deposition failuremay be generated.

Accordingly, a newly structured substrate for deposition mask, adeposition mask and a manufacturing method thereof are required.

An embodiment is directed to providing a deposition mask having uniformthrough-holes.

An embodiment is directed to providing a deposition mask having uniformand fine through-holes.

A metal plate used for manufacturing a deposition mask includes: a basemetal plate; a first surface layer disposed on a first surface of thebase metal plate; and a second surface layer disposed on a secondsurface facing the first surface of the base metal plate, wherein thefirst surface layer and the second surface layer include elementsdifferent from that of the base metal plate or composition ratiosdifferent from that of the base metal plate, and an etch rate of thebase metal plate is greater than those of the first surface layer andthe second surface layer.

A manufacturing method of a deposition mask according to an embodimentincludes: preparing a base metal plate; disposing a first surface layeron a first surface of the base metal plate; disposing a second surfacelayer on a second surface of the base metal plate; forming a photoresistlayer to dispose a first photoresist layer on the first surface layerand a second photoresist layer on the second surface layer; and etchingto form a through-hole through which a first surface hole of the firstsurface and a second surface hole of the second surface communicate witheach other, wherein the etching step has an etching factor of 2.5 ormore of at least one surface hole of the first surface hole and thesecond surface hole, the etching factor being calculated by Equation 1below.

Etching Factor=B/A   Equation 1

In the equation, the B is a depth of one surface hole of the firstsurface hole and the second surface hole etched, and the A refers to awidth of a photoresist layer extending from a bridge region on the onesurface hole and protruding in a center direction of the one surfacehole.

A deposition mask according to an embodiment includes a metal plate fora deposition mask including: a base metal plate including first andsecond surfaces facing each other; a first surface layer on the firstsurface; and a second surface layer on the second surface, wherein themetal plate for the deposition mask includes a deposition pattern regionand a non-deposition region, the deposition pattern region includes aplurality of through-holes, and the deposition pattern region is dividedinto an effective region, an outer region, and an ineffective region,and through-holes may be formed in the effective region and the outerregion.

A metal plate according to an embodiment may include a base metal plateand a surface layer disposed on the base metal plate.

The surface layer is disposed on a first surface of the base metal plateand a second surface facing the first surface, respectively, so that anetch rate on the first surface and the second surface of the base metalplate may be delayed. Accordingly, the metal plate including the surfacelayer may form uniform through-holes. That is, the metal plate used formanufacturing a deposition mask includes the through-holes with improveduniformity, so that the uniformity of a pattern formed via thethrough-holes may be improved and process efficiency may be improved byincreasing deposition efficiency of the pattern.

Therefore, an OLED panel manufactured by using the deposition maskaccording to the embodiment has excellent deposition efficiency of thepattern and deposition uniformity may be improved.

BRIEF DESCRIPTION OF DRAWINGS

FIGS. 1 to 3 are conceptual diagrams for explaining a process ofdepositing an organic material on a substrate.

FIGS. 4 to 7 are views illustrating a plan view of a metal plate for adeposition mask and a deposition mask according to an embodiment.

FIGS. 8 to 9 are views illustrating a plan view of an effective regionof a deposition mask.

FIG. 10 is a view of a first embodiment illustrating a cross-sectionalview taken along a line A-A′ in FIG. 9.

FIGS. 11 to 15 are views illustrating a manufacturing process of adeposition mask according to the first embodiment.

FIG. 16 is a photograph of a surface hole of a metal plate according toan embodiment.

FIG. 17 is a photograph of a surface hole of a metal plate according toa comparative example.

FIG. 18 is view illustrating a cross-sectional view in an etchingprocess of an embodiment.

FIG. 19 is view illustrating a cross-sectional view in an etchingprocess of a comparative example.

FIGS. 20 and 21 are views of a second embodiment illustrating across-sectional view taken along a line A-A′ in FIG. 9.

FIG. 22 is view illustrating a deposition mask according to the secondembodiment.

FIG. 23 is a view for explaining easiness of forming a through-holeaccording to a decrease in thickness of a metal plate for a depositionmask.

FIG. 24 is a view for explaining easiness of forming a through-holeaccording to an increase of an etching factor.

FIGS. 25 to 30 are views illustrating a manufacturing process of adeposition mask according to FIG. 22.

FIG. 31 is another view illustrating a through-hole of a deposition maskaccording to a second embodiment.

FIG. 32 is still another view illustrating a through-hole of adeposition mask according to the second embodiment.

MODES OF THE INVENTION

Hereinafter, embodiments will be described in detail with reference tothe accompanying drawings.

In describing with reference to the accompanying drawings, like drawingnumerals are used to designate identical elements, and redundantdescription thereof will be omitted.

Although terms such as “first”, “second”, etc. may be used to describeelements, the above-described elements should not be limited by theabove terms, and are only used to distinguish one element from another.

Also, when a part is referred to as “including” an element, it meansthat the part may include other elements as well without excluding theother elements unless specifically stated otherwise.

A process for depositing an organic material on a substrate will bedescribed with reference to FIGS. 1 to 3.

FIG. 1 is a view illustrating an organic material deposition apparatusin which a deposition mask 100 according to an embodiment is included.

The organic material deposition apparatus may include a deposition mask100, a mask frame 200, a substrate 300, an organic material depositioncontainer 400, and a vacuum chamber 500.

The deposition mask 100 may include a plurality of through-holes TH. Thedeposition mask 100 may be a substrate for deposition mask including aplurality of through-holes TH. At this point, the through-holes may beformed to correspond to patterns to be formed on the substrate.

The mask frame 200 may include an opening. The plurality ofthrough-holes of the deposition mask 100 may be disposed on a regioncorresponding to the opening. Accordingly, organic material supplied tothe organic material deposition container 400 may be deposited on thesubstrate 300. The deposition mask may be disposed and fixed on the maskframe 200. For example, the deposition mask may be tensioned and fixedon the mask frame 200 by welding.

Referring to FIGS. 1 and 2, the deposition mask 100 may be pulled inopposite directions at an end disposed on the outermost portion of thedeposition mask 100. In the deposition mask 100, one end of thedeposition mask 100 and the other end opposite to the one end may bepulled in opposite directions in a longitudinal direction of thedeposition mask 100. The one end and the other end of the depositionmask 100 may face each other and be disposed in parallel. The one end ofthe deposition mask 100 may be one of end portions forming four sidesurfaces disposed on the outermost portion of the deposition mask 100.For example, the deposition mask 100 may be pulled at a force of 0.4 to1.5 kgf. Accordingly, the tensioned deposition mask 100 may be placed onthe mask frame 200.

Next, the deposition mask 100 may be fixed to the mask frame 200 bywelding a side region, that is, the end portion of the deposition mask100. Subsequently, a portion of the deposition mask 100 disposed outsidethe mask frame 200 may be removed by a method such as cutting. Forexample, when the deposition mask 100 is deformed in the welding processand the deposition mask 100 is disposed in a region excluding fixingregions of the deposition mask 100 and the mask frame 200, a portion ofthe deposition mask 100 may be removed.

Referring to FIGS. 1 and 3, the substrate 300 may be a substrate usedfor manufacturing a display device. Patterns of red (R), green (G), andblue (B) may be formed on the substrate 300 to form a pixel that isthree primary colors of light.

The organic material deposition container 400 may be a crucible. Anorganic material may be disposed at an inside of the crucible.

As a heat source and/or current is supplied to the crucible in thevacuum chamber 500, the organic material may be deposited on thesubstrate 300.

FIG. 3 is an enlarged view of one through-hole of the deposition mask100.

The deposition mask 100 may include a first surface 101 and a secondsurface 102 facing the first surface.

The first surface 101 of the deposition mask 100 may include a firstsurface hole V1 and the second surface 102 of the deposition mask 100may include a second surface hole V2.

The through-hole may be formed by a connecting part CA through which thefirst surface hole V1 and the second surface hole V2 communicate witheach other.

A width of the second surface hole V2 may be greater than that of thefirst surface hole V1. At this time, the width of the first surface holeV1 may be measured at the first surface 101, and the width of the secondsurface hole V2 may be measured at the second surface 102.

The first surface hole V1 may be disposed toward the substrate 300.Accordingly, the first surface hole V1 may have a shape corresponding toa deposition material D, that is, a pattern.

The second surface hole V2 may be disposed toward the organic materialdeposition container 400. Accordingly, the second surface hole V2 mayaccommodate the organic material supplied from the organic materialdeposition container 400 in a wide width, and a fine pattern may beformed quickly on the substrate 300 through the first surface hole V1having a width smaller than that of the second surface hole V2.

FIGS. 4 to 7 are views illustrating plan views of a substrate for adeposition mask and a deposition mask according to an embodiment.

Referring to FIGS. 4 to 7, a substrate for a deposition mask and adeposition mask according to an embodiment may include a depositionpattern region DA and a non-deposition region NDA.

The deposition pattern region DA may be a region for depositing anorganic material through a deposition pattern portion.

The deposition pattern region DA may include a plurality of depositionpattern portions AA1, AA2, and AA3 included in one deposition mask.

The plurality of deposition pattern portions may include a firsteffective region AA1, a second effective region AA2, and a thirdeffective region AA3. One deposition pattern portion may be any one ofthe first effective region AA1, the second effective region AA2, and thethird effective region AA3.

In the case of a small-sized display device such as a smartphone, onedeposition pattern portion included in one deposition mask may be onefor forming one display device. Accordingly, one deposition mask mayinclude a plurality of deposition pattern portions, and a plurality ofdisplay devices may be formed at the same time. Therefore, thedeposition mask according to an embodiment may improve processefficiency.

Alternatively, in the case of a large-sized display device such as atelevision, a plurality of deposition pattern portions included in onedeposition mask may be a part for forming one display device. At thistime, the plurality of deposition pattern portions may be for preventingdeformation due to a load of the mask.

The deposition pattern region DA may include a plurality of isolationregions IA1 and IA2 included in one deposition mask.

The isolation regions IA1 and IA2 may be disposed between adjacentdeposition pattern portions. The isolation region may be a spaced regionbetween the plurality of deposition pattern portions. For example, afirst isolation region IA1 may be disposed between the first effectiveregion AA1 and the second effective region AA2. For example, a secondisolation region IA2 may be disposed between the second effective regionAA2 and the third effective region AA3. The isolation region allows theadjacent deposition pattern portions to be distinguished, so that theplurality of deposition pattern portions may be supported by onedeposition mask.

The deposition mask may include a non-deposition region NDA on both sideportions in a longitudinal direction of the deposition pattern regionDA. The deposition mask according to an embodiment may include thenon-deposition region NDA on both sides in a horizontal direction of thedeposition pattern region DA.

The non-deposition region NDA of the deposition mask may be a region notinvolved in a deposition.

The non-deposition region NDA may include frame fixing regions FA1 andFA2 for fixing to a mask frame. For example, the non-deposition regionNDA of the deposition mask may include a first frame fixing region FA1on one side of the deposition pattern region DA, and may include asecond frame fixing region FA2 on the other side opposite to the oneside of the deposition pattern region DA. The first frame fixing regionFA1 and the second frame fixing region FA2 may be a region fixed to themask frame by welding.

The non-deposition region NDA may include half etching portions HF1 andHF2. For example, the non-deposition region NDA of the deposition maskmay include a first half etching portion HF1 on one side of thedeposition pattern region DA, and may include a second half etchingportion HF2 on the other side opposite to the one side of the depositionpattern region DA. The first half etching portion HF1 and the secondhalf etching portion HF2 may be regions in which grooves are formed in adepth direction of the deposition mask. Since the first half etchingportion HF1 and the second half etching portion HF2 may have grooveshaving a thickness of about ½ of a thickness of the deposition mask, itis possible to disperse a stress when the deposition mask is pulled.

In addition, the half etching portion may be formed simultaneously whenthe first surface hole or the second surface hole is formed. Through thesame, process efficiency may be improved.

Further, a surface layer may be formed in the deposition pattern regionDA region, the surface layer may not be formed in the non-depositionregion NDA, or the surface layer may be formed on only a part of a firstsurface or a second surface of the substrate, or the surface layer maybe formed on only a part of the first surface, so that it is possible toadjust stress dispersion by forming an etching factor of the halfetching portion differently from that of a first surface hole or asecond surface hole.

The half etching portion may be formed in a ineffective region UA of thedeposition pattern region DA. In order to disperse the stress at thetime of pulling the deposition mask, a plurality of the half etchingportions may be disposed to be dispersed in all or a part of theineffective region UA.

In addition, the half etching portion may be formed in a frame fixingregion and/or a peripheral region of the frame fixing region.Accordingly, it is possible to uniformly disperse the stress of thedeposition mask, which is generated when the deposition mask is fixed onthe frame and/or a deposition material is deposited after fixing thedeposition mask on the frame. Accordingly, it is possible to maintainthe deposition mask so as to have uniform through-holes.

The frame fixing regions FA1 and FA2 for fixing on the mask frame of thenon-deposition region NDA may be disposed between the half etchingportions HF1 and HF2 of the non-deposition region NDA and effectiveregions of the deposition pattern region DA adjacent to the half etchingportions HF1 and HF2. For example, the first frame fixing region FA1 maybe disposed between the first half etching portion HF1 of thenon-deposition region NDA and the first effective region AA1 of thedeposition pattern region DA adjacent to the first half etching portionHF1. For example, the second frame fixing region FA2 may be disposedbetween the second half etching portion HF2 of the non-deposition regionNDA and the third effective region AA3 of the deposition pattern regionDA adjacent to the second half etching portion HF2. Accordingly, it ispossible to simultaneously fix a plurality of deposition patternportions.

The deposition mask may include a semicircular shaped open portion atboth ends in a horizontal direction X. The non-deposition region NDA ofthe deposition mask may include one semicircular shaped open portion ateach of both ends in the horizontal direction. For example, thenon-deposition region NDA of the deposition mask may include an openportion of which a center in a vertical direction Y is opened on oneside in the horizontal direction. For example, the non-deposition regionNDA of the deposition mask may include the open portion of which thecenter in the vertical direction is opened on the other side opposite tothe one side in the horizontal direction. That is, both ends of thedeposition mask may include the open portion at ½ point of a length inthe vertical direction. For example, both ends of the deposition maskmay be shaped like a horseshoe.

The half etching portion may be formed in various shapes.

Referring to FIGS. 4 to 6, the half etching portion may include asemicircular shaped groove portion. The groove may be formed on at leastone of a first surface 101 and a second surface 102 of the depositionmask. Preferably, the half etching portion may be formed on a surfacecorresponding to the first surface hole (a surface side to bedeposited). Accordingly, the half etching portion may disperse a stressthat may be generated due to a difference in size between the firstsurface hole and the second surface hole.

Alternatively, the half etching portion may be formed on both surfacesof the first surface and the second surface to disperse a stress of thefirst surface and the second surface. At this time, the half etchingregion of the half etching portion may be wider at a surfacecorresponding to the first surface hole (a surface side to bedeposited). That is, the deposition mask according to an embodiment mayinclude the half etching portion by forming grooves on the first surfaceand the second surface of the deposition mask, respectively.Specifically, a depth of the groove of the half etching portion formedon the first surface may be greater than a depth of the groove of thehalf etching portion formed on the second surface. Accordingly, the halfetching portion may disperse the stress that may be generated due to thedifference in size between the first surface hole and the second surfacehole. Since the surface areas of the first surface and the secondsurface of the deposition mask may be made similar to each other byformation of the first surface hole, the second surface hole, and thehalf etching portion, it is possible to prevent the through-hole frombeing displaced.

In addition, the grooves formed on the first surface and the secondsurface may be formed so as to be displaced from each other. Through thesame, it is possible to prevent the half etching portion from formingthe through-hole.

The half etching portion may include a curved surface and a flatsurface.

The flat surface of the first half etching portion HF1 may be disposedto be adjacent to the first effective region AA1, and the flat surfacemay be disposed horizontally at an end in a longitudinal direction ofthe deposition mask. The curved surface of the first half etchingportion HF1 may have a convex shape toward one end in the longitudinaldirection of the deposition mask. For example, the curved surface of thefirst half etching portion HF1 may be formed such that a ½ point of alength in a vertical direction of the deposition mask corresponds to theradius of a semicircular shape.

The flat surface of the second half etching portion HF2 may be disposedto be adjacent to the third effective region AA3, and the flat surfacemay be disposed horizontally at an end in the longitudinal direction ofthe deposition mask. The curved surface of the second half etchingportion HF2 may have a convex shape toward the other end in thelongitudinal direction of the deposition mask. For example, the curvedsurface of the second half etching portion HF2 may be formed such that a½ point of a length in the vertical direction of the deposition maskcorresponds to the radius of a semicircular shape.

Meanwhile, a curved surface of the open portion positioned at both endsof the deposition mask may be directed to the half etching portion.Accordingly, the open portion positioned at both ends of the depositionmask may have the shortest separation distance at the first or secondhalf etching portion and a ½ point of a length in the vertical directionof the deposition mask.

Referring to FIG. 7, the half etching portion may have a rectangularshape. The first half etching portion HF1 and the second half etchingportion HF2 may have a rectangular shape or a square shape.

The deposition mask according to an embodiment may include a pluralityof half etching portions. The deposition mask according to theembodiment may include a plurality of half etching portions in at leastone of the deposition pattern region DA and the non-deposition regionNDA. The deposition mask according to the embodiment may include a halfetching portion only in the ineffective region UA. The ineffectiveregion UA may be a region other than the effective region AA.

Referring to FIGS. 4 and 7, the deposition mask according to anembodiment may include two half etching portions. For example, the halfetching portion may include an even number of half etching portions. Thedeposition mask according to the embodiment may be disposed only in thenon-deposition region NDA.

It is preferable to form the half etching portion to be symmetric in anX-axis direction or in a Y-axis direction with respect to a center ofthe mask. Through the same, it possible to equalize a tensile force inboth directions.

Referring to FIG. 5, the deposition mask according to an embodiment mayinclude four half etching portions. For example, the half etchingportion may include an even number of half etching portions. Thedeposition mask according to the embodiment may include a plurality ofhalf etching portions only in the non-deposition region NDA.

A third half etching portion HF3 may be further included between thefirst half etching portion HF1 and the first effective region AA1. Forexample, the third half etching portion HF3 may be disposed between thefirst frame fixing region FA1 and the first effective region AA1.

A fourth half etching portion HF4 may be further included between thesecond half etching portion HF2 and the third effective region AA3. Forexample, the fourth half etching portion HF4 may be disposed between thesecond frame fixing region FA2 and the third effective region AA3.

The first half etching portion HF1 disposed at a position in thehorizontal direction corresponding to each other may have a shapecorresponding to that of the second half etching portion HF2. The thirdhalf etching portion HF3 disposed at a position in the horizontaldirection corresponding to each other may have a shape corresponding tothat of the fourth half etching portion HF4.

The first half etching portion HF1 disposed at different positions mayhave a shape different from that of any one of the third half etchingportion HF3 and the fourth half etching portion HF4. However, theembodiment is not limited thereto, and all of the first half etchingportion HF1, the second half etching portion HF2, the third half etchingportion HF3 and the fourth half etching portion HF4 may have the sameshape. Although four half etching portions have been described in theembodiment, the half etching portion may be formed in various shapes andin various numbers within a range formed in the ineffective region UA.That is, if the shape of the half etching portion is formed to bemutually symmetrical with respect to the center in the horizontaldirection X of the deposition mask, any shape may be acceptable. Inaddition, the number of the half etching portions may be six or more.

The third half etching portion HF3 and the fourth half etching portionHF4 may have a square shape. For example, the third half etching portionHF3 and the fourth half etching portion HF4 may have a rectangularshape. The third half etching portion HF3 and the fourth half etchingportion HF4 may have a rectangular shape extending in the verticaldirection of the deposition mask. Specifically, the third half etchingportion HF3 and the fourth half etching portion HF4 may have a length inthe vertical direction Y longer than a length in the horizontaldirection X. Accordingly, the half etching portion may effectivelycontrol a stress generated when the deposition mask is fixed to a frame.

Referring to FIG. 6, the deposition mask according to an embodiment mayinclude four half etching portions. For example, the half etchingportion may include an even number of half etching portions. Thedeposition mask according to the embodiment may include a plurality ofhalf etching portions in the non-deposition region NDA and thedeposition pattern region DA, respectively.

The non-deposition region NDA may include the first half etching portionHF1 and the second half etching portion HF2.

The deposition pattern region DA may include a third half etchingportion HF3 and a fourth half etching portion HF4.

The third half etching portion HF3 may be disposed between the firsteffective region AA1 and the second effective region AA2. For example,the third half etching portion HF3 may be disposed in the firstisolation region IA1.

The fourth half etching portion HF3 may be disposed between the secondeffective region AA2 and the third effective region AA3. For example,the fourth half etching portion HF4 may be disposed in the secondisolation region IA2.

The first half etching portion HF1 disposed at a position in thehorizontal direction corresponding to each other may have a shapecorresponding to the second half etching portion HF2. The third halfetching portion HF3 disposed at a position in the horizontal directioncorresponding to each other may have a shape corresponding to the fourthhalf etching portion HF4.

The first half etching portion HF1 disposed at different positions mayhave a shape different from any one of the third half etching portionHF3 and the fourth half etching portion HF4. However, the embodiment isnot limited thereto, and all of the first half etching portion HF1, thesecond half etching portion HF2, the third half etching portion HF3 andthe fourth half etching portion HF4 may have the same shape.

The third half etching portion HF3 and the fourth half etching portionHF4 may have a quadrilateral shape. For example, the third half etchingportion HF3 and the fourth half etching portion HF4 may have arectangular shape. The third half etching portion HF3 and the fourthhalf etching portion HF4 may have a rectangular shape extending in thevertical direction of the deposition mask. Specifically, the third halfetching portion HF3 and the fourth half etching portion HF4 may have alength in the vertical direction Y longer than the length in thehorizontal direction X.

A length in a vertical direction Y of the open portion positioned atboth ends of the deposition mask may correspond to the length in thevertical direction of the half etching portion or may be different fromeach other.

For example, referring to FIGS. 4 to 6, a length d1 in a verticaldirection of a flat surface portion of the first half etching portionHF1 or the second half etching portion HF2 may be greater than a lengthd2 in a vertical direction of the open portion.

For example, referring to FIGS. 5 and 6, a length d3 in a verticaldirection of the third half etching portion HF3 or the fourth halfetching portion HF4 may be greater than the length d2 in the verticaldirection of the open portion. The length d3 in the vertical directionof the third half etching portion HF3 or the fourth half etching portionHF4 may correspond to the length d1 in the vertical direction of theflat surface portion of the first half etching portion HF1 or the secondhalf etching portion HF2.

For example, referring to FIG. 7, a length d1 in a vertical direction ofthe first half etching portion HF1 or the second half etching portionHF2 may correspond to the length d2 in the vertical direction of theopen portion. Accordingly, when the deposition mask is pulled, a stressmay be uniformly dispersed, so that the deformation (wave deformation)of the deposition mask may be reduced. Therefore, the deposition maskaccording to an embodiment may have uniform through-holes, so that thedeposition efficiency of the pattern may be improved.

Preferably, the length d1 in the vertical direction of the first halfetching portion HF1 or the second half etching portion HF2 may be 80 to200% of the length d2 in the vertical direction of the open portion(d1:d2=0.8 to 2:1). The length d1 in the vertical direction of the firsthalf etching portion HF1 or the second half etching portion HF2 may be90 to 150% of the length d2 in the vertical direction of the openportion (d1:d2=0.9 to 1.5:1). The length d1 in the vertical direction ofthe first half etching portion HF1 or the second half etching portionHF2 may be 95 to 110% of the length d2 in the vertical direction of theopen portion (d1:d2=0.95 to 1.1:1).

In addition, the length d1 in the vertical direction of the flat surfaceportion of the second half etching portion HF2 and the length d3 in thevertical direction of the fourth half etching portion HF4 may correspondto a length in a vertical direction of the first effective region AA1.Through the same, a tensile force may be uniformly applied to thethrough-hole formed in the effective region.

Preferably, the length d1 in the vertical direction of the first halfetching portion HF1 or the second half etching portion HF2 may be 80 to120% of the length in the vertical direction of the effective region.

Preferably, the length d3 in the vertical direction of the third halfetching portion HF3 or the fourth half etching portion HF4 may be 80 to120% of the length in the vertical direction of the effective region.

With reference to an enlarged view of FIG. 4, through-holes included inan effective region and an ineffective region will be described.Although enlarged views are not shown in FIGS. 5 to 7, it is obviousthat the effective region and the ineffective region includethrough-holes.

The deposition mask may include an effective region AA and anineffective region UA. The deposition mask 100 may include an effectiveregion AA including a plurality of through-holes TH and a bridge regionBR, and an ineffective region UA disposed at an outer periphery of theeffective region.

The effective region AA may be an inner region when an outer peripheryof through-holes positioned at the outermost portion for depositing anorganic material among a plurality of through-holes is connected. Theineffective region UA may be an outer region when the outer periphery ofthe through-holes positioned at the outermost portion for depositing theorganic material among the plurality of through-holes is connected.

The ineffective region UA is a region excluding the effective region ofthe deposition pattern region DA and the non-deposition region NDA. Theineffective region UA may include outer regions OA1, OA2, and OA3surrounding an outer periphery of the effective regions AA1, AA2, andAA3.

The deposition mask according to an embodiment may include a pluralityof outer regions OA1, OA2, and OA3 positioned on an outer periphery of aplurality of deposition pattern portions. The number of the depositionpattern portions may correspond to the number of the outer regions. Thatis, one deposition pattern portion may include one outer region spacedapart at a predetermined distance in the horizontal direction and thevertical direction from an end of one deposition pattern portion.

The first effective region AA1 may be included in a first outer regionOA1. The first effective region AA1 may include a plurality ofthrough-holes for forming a deposition material. The first outer regionOA1 surrounding the outer periphery of the first effective region AA1may include a plurality of through-holes. The first effective region AA1may be in a quadrilateral shape, and the first outer region OA1 may bein a quadrilateral shape. For example, the first effective region AA1may be in a rectangular shape, and the first outer region OA1 may be ina rectangular shape. For example, the first effective region AA1 may bein a square shape and the first outer region OA1 may be in a squareshape.

The first outer region OA1 may further include two through-holes in thehorizontal direction and the vertical direction, respectively, from thethrough-hole positioned at the outermost portion of the first effectiveregion AA1. For example, in the first outer region OA1, twothrough-holes may be disposed in a row in the horizontal direction at anupper portion and a lower portion of the through-hole positioned at theoutermost portion of the first effective region AA1, respectively. Forexample, in the first outer region OA1, two through-holes may bedisposed in a row in the vertical direction at the left side and theright side of the through-hole positioned at the outermost portion ofthe first effective region AA1, respectively. The plurality ofthrough-holes included in the first outer region OA1 is for reducingetching failure of the through-holes positioned at the outermost portionof the effective region. Accordingly, the deposition mask according tothe embodiment may improve the uniformity of the plurality ofthrough-holes positioned in the effective region, and may improve thequality of the deposition pattern produced through the same.

A through-hole set of the first outer region OA1 in which onethrough-hole positioned at an upper portion and a lower portion of theoutermost portion of the first effective region AA1, respectively isdisposed in a row in the horizontal direction, may be in a shapecorresponding to that of the through-holes of the first effective regionAA1. In addition, a through-hole set of the first outer region OA1 inwhich one through-hole positioned at the left side and the right side ofthe outermost portion of the first effective region AA1, respectively isdisposed in a row in the vertical direction, may be in a shapecorresponding to that of the through-holes of the first effective regionAA1. Accordingly, the uniformity of the through-hole included in thefirst effective region AA1 may be improved.

The through-hole included in the effective region may have a shapepartially corresponding to that of the through-hole included in theineffective region. The through-hole included in the effective regionmay have a different shape from that of a through-hole positioned at anedge portion of the ineffective region.

Four edge holes EH positioned at an outermost corner of the first outerregion OA1 may have a different shape from that of the through-holeincluded in the first effective region AA1.

For example, the four edge holes EH positioned at the outermost cornerof the first outer region OA1 may have a circular shape. Here, thecircular shape may mean a shape including a curved surface as a whole.

For example, the through-hole included in the first effective region AA1may have a quadrilateral shape. Here, the quadrilateral shape may be arectangular shape, and may mean a rectangular shape with roundedcorners. That is, the through-hole included in the effective region AA1may have different diameters in the horizontal direction and in thevertical direction.

The diameter of the edge hole EH may be different from any one ofdiameters in the horizontal direction and in the vertical direction ofthe through-hole included in the effective region AA1. For example, asshown in FIG. 4, the diameter of the edge hole EH may be different fromthe diameter in the horizontal direction of the through-hole included inthe effective region AA1. The diameter of the edge hole EH may be thesame as the diameter in the vertical direction of the through-holeincluded in the effective region AA1.

The through-hole included in a remaining ineffective region excludingthe edge hole EH may have a shape corresponding to that of thethrough-hole included in the effective region.

In addition, the through-hole included in the ineffective region mayhave a different shape from that of the through-hole included in theeffective region. The difference in a stress due to the position of thedeposition mask may be adjusted through the same.

A through-hole edge portion is formed in the ineffective region UA, anda deposition defect may be removed at the edge portion of the effectiveregion by the edge portion. That is, in the embodiment, since the edgehole EH of the deposition mask is formed in the non-effective region,the through-hole positioned at the edge portion of the effective regionmay be positioned at an inner side than the edge hole EH. Accordingly,one of the through-hole positioned at the edge portion of the effectiveregion and the through-hole positioned inside the effective region mayhave the same deposition effect. Specifically, since the through-hole isincluded in the ineffective region UA, the uniformity of thethrough-hole positioned in the edge portion of the effective region andthe through-hole positioned in the effective region may be improved.

The second effective region AA2 may be included in the second outerregion OA2. The second effective region AA2 may include a plurality ofthrough-holes for forming a deposition material. The second outer regionOA2 surrounding the outer periphery of the second effective region AA2may include a plurality of through-holes.

The second effective region AA2 may be in a shape corresponding to thatof the first effective region AA1. The second outer region OA2 may be ina shape corresponding to that of the first outer region OA1.

The second outer region OA2 may further include two through-holes in thehorizontal direction and the vertical direction, respectively, from thethrough-hole positioned at the outermost portion of the second effectiveregion AA2. For example, in the second outer region OA2, twothrough-holes may be disposed in a row in the horizontal direction at anupper portion and a lower portion of the through-hole positioned at theoutermost portion of the second effective region AA2, respectively. Forexample, in the second outer region OA2, two through-holes may bedisposed in a row in the vertical direction at the left side and theright side of the through-hole positioned at the outermost portion ofthe second effective region AA2, respectively. The plurality ofthrough-holes included in the second outer region OA2 is for reducingetching failure of the through-holes positioned at the outermost portionof the effective region. Accordingly, the deposition mask according tothe embodiment may improve the uniformity of the plurality ofthrough-holes positioned in the effective region, and may improve thequality of the deposition pattern produced through the same.

A through-hole set of the second outer region OA2 in which onethrough-hole positioned at an upper portion and a lower portion of theoutermost portion of the second effective region AA2, respectively isdisposed in a row in the horizontal direction, may be in a shapecorresponding to that of the through-holes of the second effectiveregion AA2. In addition, a through-hole set of the second outer regionOA2 in which one through-hole positioned at the left side and the rightside of the outermost portion of the second effective region AA2,respectively is disposed in a row in the vertical direction, may be in ashape corresponding to that of the through-holes of the second effectiveregion AA2. Accordingly, the uniformity of the through-hole included inthe second effective region AA2 may be improved.

Four through-holes positioned at an outermost corner of the second outerregion OA2 may have a different shape from that of the through-holeincluded in the second effective region AA2.

For example, the four edge holes EH positioned at the outermost cornerof the second outer region OA2 may have a circular shape. Here, thecircular shape may mean a shape including a curved surface as a whole.The edge hole EH included in the second outer region OA2 may include ashape corresponding to that of the edge hole EH included in the firstouter region OA1.

For example, the through-hole included in the first effective region AA1may have a quadrilateral shape. The through-hole included in the secondeffective region AA2 may include a shape corresponding to that of thethrough-hole included in the first effective region AA1.

The third effective region AA3 may be included in the third outer regionOA3. The third effective region AA3 may include a plurality ofthrough-holes for forming a deposition material. The third outer regionOA3 surrounding the outer periphery of the third effective region AA3may include a plurality of through-holes.

The third effective region AA3 may be in a shape corresponding to thatof the first effective region AA1. The third outer region OA3 may be ina shape corresponding to that of the first outer region OA1.

The third outer region OA3 may further include two through-holes in thehorizontal direction and the vertical direction, respectively, from thethrough-hole positioned at the outermost portion of the third effectiveregion AA3, respectively. For example, in the third outer region OA3,two through-holes may be disposed in a row in the horizontal directionat an upper portion and a lower portion of the through-hole positionedat the outermost portion of the third effective region AA3. For example,in the third outer region OA3, two through-holes may be disposed in arow in the vertical direction at the left side and the right side of thethrough-hole positioned at the outermost portion of the third effectiveregion AA3, respectively. The plurality of through-holes included in thethird outer region OA3 is for reducing etching failure of thethrough-holes positioned at the outermost portion of the effectiveregion. Accordingly, the deposition mask according to the embodiment mayimprove the uniformity of the plurality of through-holes positioned inthe effective region, and may improve the quality of the depositionpattern produced through the same.

A through-hole set of the third outer region OA3 in which onethrough-hole positioned at an upper portion and a lower portion of theoutermost portion of the third effective region AA3, respectively isdisposed in a row in the horizontal direction, may be in a shapecorresponding to that of the through-holes of the third effective regionAA3. In addition, a through-hole set of the third outer region OA3 inwhich one through-hole positioned at the left side and the right side ofthe outermost portion of the third effective region AA3, respectively isdisposed in a row in the vertical direction, may be in a shapecorresponding to that of the through-holes of the third effective regionAA3. Accordingly, the uniformity of the through-hole included in thethird effective region AA3 may be improved.

Four through-holes EH positioned at an outermost corner of the thirdouter region OA3 may have a different shape from that of thethrough-hole included in the third effective region AA3.

For example, the four edge holes EH positioned at the outermost cornerof the third outer region OA3 may have a circular shape. Here, thecircular shape may mean a shape including a curved surface as a whole.The edge hole EH included in the third outer region OA3 may include ashape corresponding that of to the edge hole EH included in the firstouter region OA1.

For example, the through-hole included in the third effective region AA3may have a quadrilateral shape. The through-hole included in the thirdeffective region AA3 may include a shape corresponding to that of thethrough-hole included in the first effective region AA1.

FIGS. 8 and 9 are views illustrating a plan view of an effective regionof a deposition mask. FIGS. 8 and 9 are plan views of any one effectiveregion of the first effective region AA1, the second effective regionAA2, and the third effective region AA3. FIGS. 8 and 9 are views forillustrating arrangement of through-holes, and the deposition maskaccording to an embodiment is not limited to a number of through-holesin the drawings.

The deposition mask 100 may include a plurality of through-holes. Theplurality of through-holes shown in FIGS. 8 and 9 may be the secondsurface hole V2. In the case of measuring a diameter Cx in thehorizontal direction and a diameter Cy in the vertical direction of areference hole which is any one of through-holes, a deviation betweenthe diameters Cx in the horizontal direction and a deviation between thediameters Cy in the vertical direction of each of holes (six in total inthe illustrated drawing) adjacent to the reference hole may be realizedas 2% to 10%. That is, when a size deviation between the adjacent holesof one reference hole is realized as 2% to 10%, deposition uniformitymay be secured.

For example, the size deviation between the reference hole and theadjacent holes may be 4% to 9%. For example, the size deviation betweenthe reference hole and the adjacent holes may be 5% to 7%. For example,the size deviation between the reference hole and the adjacent holes maybe 2% to 5%.

When the size deviation between the reference hole and the adjacentholes is less than 2%, an occurrence ratio of moire in an OLED panelafter deposition may be increased. If the size deviation between thereference hole and the adjacent holes is more than 10%, an occurrenceratio of color unevenness in the OLED panel after deposition may beincreased.

An average deviation of the diameters of the through-holes may be ±5 μm.For example, the average deviation of the diameters of the through-holesmay be ±3 μm. In the embodiment, deposition efficiency may be improvedby realizing the size deviation between the reference hole and theadjacent holes within ±3 μm.

The through-holes may be disposed in a row or may be disposed crossingeach other according to a direction.

For example, referring to FIG. 8, the through-holes may be disposed in arow in a vertical axis, and may be disposed in a row in a horizontalaxis.

For example, referring to FIG. 9, the through-holes may be disposed in arow in a vertical axis, and may be disposed crossing each other in ahorizontal axis.

Alternatively, the through-holes may be disposed crossing each other ina vertical axis, and may be disposed in a row in a horizontal axis.

In the through-hole, a first diameter Cx measured in the horizontaldirection and a second diameter Cy measured in the vertical directionmay correspond to each other or may be different from each other. In thethrough-hole, a third diameter measured in a first diagonal directioncorresponding to a sectional direction of A-A′ and a fourth diametermeasured in a second diagonal direction crossing the first diagonaldirection may correspond to each other or be different from each other.The through-hole may be rounded.

Hereinafter, a deposition mask according to a first embodiment will bedescribed in FIGS. 10 to 15.

FIG. 10 is an enlarged cross-sectional view of a plurality ofthrough-holes of a deposition mask according to the first embodiment.

A metal plate included in a deposition mask according to an embodimentmay include: a base metal plate including a first surface and a secondsurface facing each other; a first surface layer disposed on the firstsurface; and a second surface layer disposed on the second surface,wherein the first surface layer and the second surface layer may includean element different from that of the base metal plate, or an elementalcontent may be different. In this manner, an etch rate of the base metalplate may be different from those of the first surface layer and thesecond surface layer. The first surface layer and the second surfacelayer may be a metal surface layer, respectively.

A deposition mask according to an embodiment may include: a base metalplate; a first surface layer disposed on a first surface of the basemetal plate; and a second surface layer disposed on a second surfaceopposite to the first surface of the metal layer, wherein the firstsurface layer and the second surface layer may include an elementdifferent from that of the base metal plate, or an elemental content maybe different. In this manner, an etch rate of the base metal plate maybe different from those of the first surface layer and the secondsurface layer. The deposition mask according to an embodiment mayinclude a plurality of through-holes passing through which the basemetal plate, the first surface layer, and the second surface layer, andincluding a first surface hole and a second surface hole communicatingwith each other. The deposition mask according to an embodiment mayinclude a bridge region between each of the through-holes, and the firstsurface layer or the second surface layer may be disposed on the bridgeregion.

The metal plate may include a central region including a plurality ofthrough-holes and an outer region positioned at an outer boundary of thecentral region. The central region may be a region that is involved inpattern formation, and the outer region may be a region, which is notinvolved in pattern formation. For example, the central region may be aneffective region, and the outer region may be a region other than theeffective region. A thickness of the first surface layer disposed at thecentral region may correspond to a thickness of the first surface layerdisposed at the outer region, and a thickness of the second surfacelayer disposed at the central region may correspond to a thickness ofthe second surface layer disposed at the outer region.

Referring to FIG. 10, a deposition mask 100 may include a base metalplate 100 a and a surface layer. For example, the deposition mask 100may include the base metal plate 100 a, a first surface layer 110disposed on a first surface 101 of the base metal plate 100 a, and asecond surface layer 120 disposed on a second surface 102 opposite tothe first surface 101.

The base metal plate 100 a may include a metal material. The base metalplate 100 a may include a nickel alloy. For example, the base metalplate 100 a may be an alloy of nickel and iron. At this point, thenickel may be about 35 to 37 wt %, and the iron may be about 63 to 65 wt%. For example, the base metal plate 100 a may include an invarincluding about 35 to 37 wt % of nickel, about 63 to 65 wt % of iron,and at least one of a trace amount of C, Si, S, P, Cr, Mo, Mn, Ti, Co,Cu, Fe, Ag, Nb, V, In, and Sb. Here, the small amount may mean not morethan 1 w %. Specifically, here, the trace amount may refer to 0.5 wt %or less. However, the base metal plate 100 a is not limited thereto, andmay obviously include various metal materials.

Since the nickel alloy such as Invar has a small thermal expansioncoefficient, it has advantage that a lifetime of the deposition mask maybe increased. However, it has a problem that uniform etching for thenickel alloy such as the invar is difficult.

That is, in the nickel alloy such as the invar, the through-hole may beenlarged to a side surface as the etch rate increases in an initialstage of the etching, and thus de-filming of a photoresist layer mayoccur. In addition, when the invar is etched, it may be difficult toform a through-hole having a fine size as a size of the through-holeincreases. Further, the through-hole is formed non-uniformly, so that ayield of the mask for deposition may be deteriorated.

Therefore, in an embodiment, a surface layer for surface modificationmay be disposed on a surface of the base metal plate with differentcomposition, content, crystal structure and corrosion rate. Here, thesurface modification may mean a layer made of various materials disposedon the surface to improve an etching factor.

The metal plate for the deposition mask of an embodiment may include asurface layer for preventing rapid etching on the surface of the basemetal plate. The surface layer may be an etching barrier layer having alower etch rate than that of the base metal plate. The surface layer mayhave a different crystal plane and crystal structure from those of thebase metal plate. For example, as the surface layer includes a differentelement from that of the base metal plate, a crystal plane and a crystalstructure may be different from each other.

In the same corrosion environment, the surface layer may have adifferent corrosion potential from that of the base metal plate. Forexample, when the same etchant is applied for the same time at the sametemperature, the surface layer may have different corrosion currents orcorrosion potentials from those of the base metal plate.

The base metal plate 100 a may include an element different from that ofthe first surface layer 110. In addition, the base metal plate 100 a mayinclude an element different from that of the second surface layer 120.That is, the first surface layer 110 and the second surface layer 120may include different elements not included in the base metal plate 100a.

For example, the first surface layer 110 and the second surface layer120 may include chromium (Cr), and the base metal plate 100 a mayinclude an element other than Cr. As the first surface layer 110 and thesecond surface layer 120 include Cr, the corrosion rate at the surfaceof the metal plate may be lower than that of the surface of the basemetal plate 100 a.

Further, the content of Cr of the surface layer may be formed to behigher than that of the base metal plate, and the corrosion rate at thesurface of the metal plate may be slower than that of the base metalplate 100 a.

For example, when the base metal plate 100 a is Invar including 36 wt %nickel and 64 wt % iron, the first surface layer 110 and the secondsurface layer 120 may each be an alloy layer including 0.01 to 24 wt %Cr. At this point, the first surface layer 110 and the second surfacelayer 120 may each include 1 to 24 wt % Cr, and 76 to 99 wt % nickel(Ni) or 76 to 99 wt % Ni and Fe.

For example, the first surface layer 110 and the second surface layer120 may include titanium (Ti), and the base metal plate 100 a mayinclude an element other than titanium (Ti). As the first surface layer110 and the second surface layer 120 include Ti, the corrosion rate atthe surface of the metal plate may be slower than that of the surface ofthe base metal plate 100 a.

In addition, the content of Ti of the surface layer may be formed to behigher than that of the base metal plate, and the corrosion rate at thesurface of the metal plate may be slower than that of the base metalplate 100 a.

For example, when the base metal plate 100 a is Invar including 36 wt %nickel and 64 wt % iron, the first surface layer 110 and the secondsurface layer 120 may each be an alloy layer including 0.5 to 10 wt %Ti. At this point, the first surface layer 110 and the second surfacelayer 120 may each include 0.5 to 10 wt % Ti, and 90 to 99.5 wt % Ni, or90 to 99.5 wt % Ni and Fe.

For example, the first surface layer 110 and the second surface layer120 may include manganese (Mn), and the base metal plate 100 a mayinclude an element other than Mn. As the first surface layer 110 and thesecond surface layer 120 include a Mn-based alloy, the corrosion rate atthe surface of the metal plate may be slower than that of the surface ofthe base metal plate 100 a.

In addition, the content of Mn of the surface layer may be formed to behigher than that of the base metal plate, and the corrosion rate at thesurface of the metal plate may be slower than that of the base metalplate 100 a.

For example, the first surface layer 110 and the second surface layer120 may include molybdenum (Mo), and the base metal plate 100 a mayinclude an element other than Mo. As the first surface layer 110 and thesecond surface layer 120 include a Mo-based alloy, the corrosion rate atthe surface of the metal plate may be slower than that of the surface ofthe base metal plate 100 a.

In addition, the content of Mo of the surface layer may be formed to behigher than that of the base metal plate, and the corrosion rate at thesurface of the metal plate may be slower than that of the surface of thebase metal plate 100 a.

For example, the first surface layer 110 and the second surface layer120 may include silver (Ag), and the base metal plate 100 a may includean element other than Ag. As the first surface layer 110 and the secondsurface layer 120 include a Ag-based alloy, the corrosion rate at thesurface of the metal plate may be lower than that of the surface of thebase metal plate 100 a.

In addition, the content of Ag of the surface layer may be formed to behigher than that of the base metal plate, and the corrosion rate at thesurface of the metal plate may be slower than that of the base metalplate 100 a.

For example, the first surface layer 110 and the second surface layer120 may include zinc (Zn), and the base metal plate 100 a may include anelement other than Zn. As the first surface layer 110 and the secondsurface layer 120 include a Zn-based alloy, the corrosion rate at thesurface of the metal plate may be slower than that of the surface of thebase metal plate 100 a.

In addition, the content of Zn of the surface layer may be formed to behigher than that of the base metal plate, and the corrosion rate at thesurface of the metal plate may be slower than that of the surface of thebase metal plate 100 a.

For example, the first surface layer 110 and the second surface layer120 may include nitrogen (N), and the base metal plate 100 a may includean element other than N. As the first surface layer 110 and the secondsurface layer 120 include a N-based alloy, the corrosion rate at thesurface of the metal plate may be slower than that of the surface of thebase metal plate 100 a.

In addition, the content of N of the surface layer may be formed to behigher than that of the base metal plate, and the corrosion rate at thesurface of the metal plate may be slower than that of the surface of thebase metal plate 100 a.

For example, the first surface layer 110 and the second surface layer120 may include aluminum (Al), and the base metal plate 100 a mayinclude an element other than Al. As the first surface layer 110 and thesecond surface layer 120 include an Al-based alloy, the corrosion rateat the surface of the metal plate may be slower than that of the surfaceof the base metal plate 100 a.

In addition, the content of Al of the surface layer may be formed to behigher than that of the base metal plate, and the corrosion rate at thesurface of the metal plate may be slower than that of the surface of thebase metal plate 100 a.

For example, the first surface layer 110 and the second surface layer120 may include an oxygen element. That is, the first surface layer 110and the second surface layer 120 may be a metal oxide layer.Specifically, the first surface layer 110 and the second surface layer120 may include at least one of iron oxide and nickel oxide as metaloxides. The content of oxygen in the first surface layer 110 may behigher than that of oxygen in the base metal plate 100 a. The content ofoxygen in the second surface layer 120 may be higher than that of oxygenin the base metal plate 100 a. As the first surface layer 110 and thesecond surface layer 120 include the metal oxides, the corrosion rate atthe surface of the metal plate may be slower than that of the surface ofthe base metal plate 100 a.

In addition, the content of O of the surface layer may be formed to behigher than that of the base metal plate, and the corrosion rate at thesurface of the metal plate may be slower than that of the surface of thebase metal plate 100 a.

In an embodiment, the first surface layer 110 and the second surfacelayer 120 include a different element from that of the base metal plate100 a, so that the corrosion rate of the first and second surface layersmay be slower than that of the base metal plate. Accordingly, theetching factor of the deposition mask according to the embodiment may beincreased. In addition, since the deposition mask according to theembodiment may uniformly form a plurality of through-holes, thedeposition efficiency of R, G, and B patterns may be improved. Here,including different elements may mean that the base metal plate 100 aand the surface layer include at least one different element, or eventhough all the elements are the same, alloys having different contentsare included.

The base metal plate 100 a may have a different composition of includedelements from that of the first surface layer 110. In addition, the basemetal plate 100 a may have a different composition of included elementsfrom that of the second surface layer 120. That is, even though thefirst surface layer 110 and the second surface layer 120 include thesame element as the element constituting the base metal plate 100 a, thesame element may have different contents.

For example, when the base metal plate 100 a is Invar including 36 wt %nickel and 64 wt % iron, even though the first surface layer 110 and thesecond surface layer 120 include at least one of nickel and iron, thefirst surface layer 110 and the second surface layer 120 may havedifferent contents of nickel or iron from that of the base metal plate100 a.

The content of nitrogen in the first surface layer 110 may be larger orsmaller than that of the base metal plate 100 a. In addition, thecontent of nitrogen in the second surface layer 120 may be larger orsmaller than that of nitrogen in the base metal plate 100 a. Forexample, the first surface layer 110 and the second surface layer 120may include a nitrogen (N) element. Specifically, each layer of thefirst surface layer 110 and the second surface layer 120 may be anitrogen-based alloy including 20 to 70 wt % N element.

The content of iron in the first surface layer 110 may be larger orsmaller than that of the base metal plate 100 a. In addition, thecontent of iron in the second surface layer 120 may be larger or smallerthan that of iron in the base metal plate 100 a. For example, the firstsurface layer 110 and the second surface layer 120 may include an iron(Fe) element. Specifically, each layer of the first surface layer 110and the second surface layer 120 may be an iron-based alloy including 20to 70 wt % Fe element.

The first surface layer 110 and the second surface layer 120 may includean element corresponding to each other. Here, the “corresponding witheach other” may mean that a content percentage of an element is thesame, and may include an error range due to tolerance.

The first surface layer 110 and the second surface layer 120 may includeat least one metal of Ni, Cr, Fe, Ti, Mn, O, Mo, Ag, Zn, N, Al, andalloys thereof.

For example, the first surface layer 110 and the second surface layer120 may include any one single element of Ni, Cr, Fe, Ti, Mn, O, Mo, Ag,Zn, N, and Al.

For example, the first surface layer 110 and the second surface layer120 may be a binary alloy including two elements of Ni, Cr, Fe, Ti, Mn,O, Mo, Ag, Zn, N, and Al.

For example, the first surface layer 110 and the second surface layer120 may be a ternary alloy including three elements of Ni, Cr, Fe, Ti,Mn, O, Mo, Ag, Zn, N, and Al.

A thickness of the base metal plate 100 a may be greater than that ofthe surface layer. For example, a thickness T1 of the base metal plate100 a may be greater than a thickness T2 of the first surface layer 110and a thickness T3 of the second surface layer 120.

A thickness of the metal plate 100 may be 5 to 50 μm. For example, thethickness of the metal plate 100 may be 5 to 30 μm, or may be 10 to 25μm. When the thickness of the metal plate 100 is less than 5 μm,manufacturing efficiency may be low.

When the thickness of the metal plate 100 is more than 50 μm, processefficiency for forming a through-hole may be deteriorated.

The thickness T1 of the base metal plate 100 a may be 50 μm or less. Forexample, the thickness T1 of the base metal plate 100 a may be 30 μm orless. In addition, the thickness T1 of the base metal plate 100 a may be25 μm or less. Further, the thickness T1 of the base metal plate 100 amay be 20 μm or less.

The first surface layer 110 and the second surface layer 120 may have athickness corresponding to each other. Here, the “corresponding” mayinclude an error due to tolerance. The thickness T2 of the first surfacelayer 110 may be 0.5 to 1000 nm. For example, the thickness T2 of thefirst surface layer 110 may be 5 to 850 nm

When the thickness T2 of the first surface layer 110 is less than 0.5nm, the effect of lowering the etch rate on the first surface 101 may bereduced, and thus uniformity of the through-hole may be deteriorated. Inaddition, a natural oxide film of 5 nm or less may be generated.

For example, when the thickness T2 of the first surface layer 110 isless than 0.5 nm a through-hole having a large variation in thicknessand/or width is formed, so that the pattern formed by the metal platehaving the through-hole may not be uniform, and thus manufacturingefficiency of the display device may be deteriorated.

In addition, when the thickness T2 of the first surface layer 110 isless than 0.5 nm, the effect of lowering the etch rate on the firstsurface 101 may be reduced, and thus it is difficult to form athrough-hole having a fine size.

In addition, when the thickness T2 of the first surface layer 110 isless than 0.5 nm, the surface roughness of an inner circumferentialsurface of the first surface hole V1 increases, so that quality of thedeposition pattern formed through the first surface hole V1 may bedegraded, and thus process efficiency may be deteriorated.

Meanwhile, when the thickness T2 of the first surface layer 110 is morethan 1000 nm, manufacturing efficiency may be deteriorated.

The thickness T3 of the second surface layer 120 may be 0.5 to 1000 nm.For example, the thickness T3 of the second surface layer 120 may be 30to 500 nm.

When the thickness T3 of the second surface layer 120 is less than 0.5nm, the effect of lowering the etch rate on the second surface 102 maybe reduced, and thus uniformity of the through-hole may be deteriorated.For example, when the thickness T3 of the second surface layer 120 isless than 0.5 nm, a through-hole having a large variation in thicknessand/or width is formed, so that the pattern formed by the metal platehaving the through-hole may not be uniform, and thus manufacturingefficiency of the display device may be deteriorated.

In addition, when the thickness T3 of the second surface layer 120 isless than 0.5 nm, the effect of lowering the etch rate on the secondsurface 102 may be reduced, and thus it is difficult to form athrough-hole having a fine size.

In addition, when the thickness T3 of the second surface layer 120 isless than 0.5 nm, the surface roughness of an inner circumferentialsurface of the second surface hole V2 may be increased.

Meanwhile, when the thickness T3 of the second surface layer 120 is morethan 1000 nm, manufacturing efficiency may be deteriorated.

The metal plate 100 may have different widths of through-holes along thethickness direction of the through-holes. For example, a width W1 of thefirst surface hole V1 may be greater than a width W3 of the connectingpart CA. Specifically, the width of the through-hole may be reduced asthe first surface hole V1 goes from the first surface 101 toward theconnecting part CA. More specifically, the width of the through-hole maybe gradually reduced as the first surface hole V1 goes from the firstsurface 101 toward the connecting part CA.

For example, a width W2 of the second surface hole V2 may be greaterthan the width W3 of the connecting part CA. Specifically, the width ofthe through-hole may be reduced as the second surface hole V2 goes fromthe second surface 102 toward the connecting part CA. More specifically,the width of the through-hole may be gradually reduced as the secondsurface hole V2 goes from the second surface 102 toward the connectingpart CA.

The deposition mask according to an embodiment may include a pluralityof through-holes. Specifically, the metal plate may include a centralregion including the plurality of through-holes and an outer regionpositioned at the central region. At this time, a width of onethrough-hole may be 20 μm or more. For example, the width of thethrough-hole may be 20 to 40 μm. For example, at least one of the widthW1 of the first surface hole and the width W2 of the second surface holemay have a width of 20 μm or more. For example, at least one of thewidth W1 of the first surface hole and the width W2 of the secondsurface hole may have a width of 20 to 40 μm.

When the width of the through-hole is more than 40 μm, it may bedifficult to form a fine deposition pattern.

The plurality of through-holes may include a first through-hole and asecond through-hole adjacent to the first through-hole. The metal platepositioned between the first through-hole and the second through-holemay be defined as a bridge region (BR). The BR may be disposed at thecentral region.

A thickness of the first surface layer disposed at the central regionmay correspond to a thickness of the first surface layer disposed at theouter region.

A thickness of the second surface layer disposed at the central regionmay correspond to a thickness of the second surface layer disposed atthe outer region.

A first surface of the metal plate may include a first bridge region BR1and a second surface opposite to the first surface may include a secondbridge region BR2.

A metal plate, a first surface layer disposed on the first surface ofthe metal plate, and a second surface layer disposed on the secondsurface of the metal plate may be disposed at the bridge region.

A metal plate, a first surface layer disposed on the first surface ofthe metal plate, and a second surface layer disposed on the secondsurface of the metal plate may be disposed in the outer region of themetal plate.

The through-hole may be formed passing through the base metal plate, thefirst surface layer, and the second surface layer. Accordingly, the basemetal plate, the first surface layer, and the second surface layer maybe exposed at an inner side surface of the through-hole.

The inner side surface of the through-hole may include a curved surface.The inner side surface of the through-hole may include a curved surfacein whole or in part. The inner side surface of the through-hole mayinclude a curved surface of which a curvature changes. A curvature ofeach of the base metal plate, the first surface layer, and the secondsurface layer may be different from each other at the inner side surfaceof the through-hole. At this time, the curvature of each of the basemetal plate, the first surface layer and the second surface layer maymean that it is measured at ½ point of the thickness of the base metalplate, ½ point of the thickness of the first surface layer and ½ pointof the thickness of the second surface layer.

A height H2 of the second surface hole V2 may be greater than a heightH1 of the first surface hole V1.

Meanwhile, since a third surface hole V3 adjacent to the first surfacehole V1 and formed on the first surface 101 communicates with a fourthsurface hole V4 adjacent to the second surface hole V2 and formed on thesecond surface 102, through the connecting part CA, a through-hole maybe formed.

A width W5 of the fourth through-hole V4 may be greater than a width W4of the third through-hole V3. For example, the width W4 of the thirdthrough-hole V3 may be greater than a width W6 of the connecting partCA. Specifically, the width of the through-hole may be reduced as thethird surface hole V3 goes from the first surface 101 toward theconnecting part CA. Specifically, the width of the through-hole may begradually reduced as the third surface hole V3 goes from the firstsurface 101 toward the connecting part CA.

For example, the width W5 of the fourth surface hole V4 may be greaterthan the width W6 of the connecting part CA. Specifically, the width ofthe through-hole may be reduced as the fourth surface hole V4 goes fromthe second surface 102 toward the connecting part CA. More specifically,the width of the through-hole may be gradually reduced as the fourthsurface hole V4 goes from the second surface 102 toward the connectingpart CA.

A height H4 of the fourth surface hole V4 may be greater than a heightH3 of the third surface hole V3.

The etch rate of the base metal plate 100 a may be different from theetch rate of the first surface layer 110 and the second surface layer120. For example, the etch rate of the base metal plate 100 a positionedinside in the thickness direction of the metal plate may be faster thanthat of the first and second surface layers 110 and 120 positionedoutside in the thickness direction of the metal plate. In other words,the etch rate of the first surface layer 110 may be slower than that ofthe base metal plate 100 a. The etch rate of the second surface layer120 may be slower than that of the base metal plate 100 a. Specifically,the first surface layer 110 and the second surface layer 120 may includean element having higher corrosion resistance than an elementconstituting the base metal plate 100 a, so that the etch rate at thesurface layer may be slower than that of the base metal plate. That is,the surface layer may be a metal surface layer including a metal elementhaving higher corrosion resistance than the element constituting thebase metal plate.

A conventional metal plate has a problem that adjacent through-holes maybe overlapped with each other as an etch rate of an outside of the metalplate having a large contact area of an etchant is faster than that ofan inside of the metal plate. That is, in the deposition maskmanufactured using only the base metal plate 100 a, as the etch rate ofthe first surface 101 and the second surface 102 of the base metal plate100 a in contact with an etchant increases, the width of thethrough-hole formed on the first surface 101 and the second surface 102may be increased. Accordingly, it is difficult to form a through-holehaving a fine pattern, and a manufacturing yield may be lowered. Inaddition, uniformity of a plurality of through-holes may be lowered.Therefore, the OLED panel manufactured through the same may have lowdeposition efficiency of a pattern, and deposition uniformity of thepattern may be deteriorated.

Meanwhile, an embodiment may include the first surface layer 110 and thesecond surface layer 120 on both surfaces of the base metal plate 100 a,and the first surface layer 110 and the second surface layer 120 mayinclude an element different from that of the base metal plate 100 a.Accordingly, the etch rate of the first surface layer 110 and the secondsurface layer 120 may be slower than that of the base metal plate 100 a.

That is, the first surface layer 110 and the second surface layer 120may include a metal element or a metal oxide having a higher corrosionresistance than that of the base metal plate 100 a, and the firstsurface layer 110 and the second surface layer 120 are disposed at athickness of 0.5 to 1000 nm respectively, so that a fine through-holemay be formed.

For example, in the metal plate according to an embodiment, when thefirst surface layer 110 and the second surface layer 120 are disposed ata thickness of more than 5 nm and 800 nm or less, 10 nm to 600 nm, and30 nm to 500 nm, respectively, the width W1 of the first surface hole V1may correspond to the width W4 of the third through-hole V3, and thewidth W2 of the second surface hole V2 may correspond to the width W5 ofthe fourth through-hole V4. For example, in the metal plate according tothe embodiment, when the first surface layer 110 and the second surfacelayer 120 are disposed at a thickness of more than 5 nm and 800 nm orless, 10 nm to 600 nm, and 30 nm to 500 nm, respectively, the height H1of the first surface hole V1 may correspond to the height H3 of thethird surface hole V3, and the height H2 of the second surface hole V2may correspond to the height H4 of the fourth surface hole V4. That is,uniformity of the width and height of the plurality of through-holes maybe improved.

That is, the metal plate according to the embodiment may be formed suchthat the through-hole may have a small width and a deep thickness sincethe etch rate at a region in which the first surface layer 110 and thesecond surface layer 120 are disposed may be slow. Accordingly, it ispossible to prevent a de-filming phenomenon of a photoresist layer frombeing caused by a rapid etching at a metal surface.

In addition, the metal plate used for manufacturing the deposition maskaccording to an embodiment may control the etch rate at the surface, andthus a manufacturing yield of the through-hole having a fine pattern maybe improved and uniformity of the plurality of through-holes may beimproved. Accordingly, the OLED panel manufactured by using such adeposition mask has excellent deposition efficiency of the pattern andmay improve deposition uniformity. In addition, the surface layeraccording to an embodiment includes at least one of a metal or a metaloxide having high corrosion resistance, so that an adhesion force of thephotoresist layer may be improved, and thus the photoresist layer may beprevented from being de-filmed or separated in the etching process.Accordingly, the metal plate according to an embodiment may improve amanufacturing yield and process efficiency of the plurality ofthrough-holes.

Referring to FIGS. 11 to 15, the manufacturing process of a depositionmask according to a first embodiment will be described.

A deposition mask according to an embodiment may include: preparing abase metal plate; disposing a first surface layer on a first surface ofthe base metal plate; disposing a second surface layer on a secondsurface of the base metal plate; forming a photoresist layer to disposea first photoresist layer on the first surface layer and a secondphotoresist layer on the second surface layer; and an etching to form athrough-hole in which a first surface hole of the first surface and asecond surface hole of the second surface communicate with each other.In addition, the metal plate used in the deposition mask according to anembodiment may further include removing the first photoresist layer andthe second photoresist layer after the etching.

Further, the first surface layer and the second surface layer may beformed simultaneously. Accordingly, process efficiency may be improved.Furthermore, of course, the first photoresist layer and the secondphotoresist layer may be formed step by step.

In addition, the through-hole may be formed by forming the first surfacehole and the second surface hole step by step.

Further, a first photoresist for forming the first surface hole may beformed, an anti-etching protective layer may be formed at the secondsurface, and then the first surface hole may be formed, and aphotoresist for forming the second surface hole may be formed, ananti-etching protective layer may be formed at the first surface, andthen the second surface hole may be formed.

Furthermore, an embodiment may further include removing the first andsecond surface layers after the removing of the photoresist layer. Inthis manner, foreign matters generated due to the surface layer may beprevented during deposition of an OLED. In this case, the content of Niof the first surface from which the surface layer has been removed maybe different from the content of Ni of a center, which is one half of athickness of the base metal plate. Preferably, the content of Ni of thefirst surface may be greater than that of the center, which is one-halfof the thickness of the base metal plate.

First, a first step is a preparing step of a base metal plate 100 a. Anickel alloy may be prepared for the base metal plate 100 a. Forexample, the base metal plate 100 a may be an alloy of nickel and iron.

In addition, impurities may be contained for improving a strength. Theimpurities may include at least one of C, Si, Mn, P, S, Al and Cr, andmay be 2 w % or less, 1.7 W % or less, or 1.5 w % or less of the entirebase metal plate. When exceeding 2 w %, the thermal expansioncharacteristic which is a basic characteristic of Invar may bedeteriorated.

The preparing step of the base metal plate may include various thicknessreduction steps. For example, the base metal plate may further include athickness reduction step by a rolling step.

That is, a second step may be a rolling step of the base metal plate 100a. Referring to FIG. 11, the base metal plate 100 a may have a thicknessT1 of 5 μm to 50 μm. For example, the base metal plate 100 a may have athickness T1 of 30 μm or less. Here, the thickness of the base metalplate 100 a may be a thickness measured after a rolling process. At thistime, the rolling step may be a cold rolling step. That is, an initialmetal substrate has a thickness of more than 30 μm, the base metal plateprocessed by the thickness reduction step by the rolling step may have athickness of 30 μm or less (e.g. 25 μm, 20 μm).

A third step is a disposing step of the first surface layer on the firstsurface of the base metal plate.

A fourth step is a disposing step of the second surface layer on thesecond surface of the base metal plate.

Referring to FIG. 12, first and second surface layers 110 and 120 may beformed on the base metal plate 100 a. For example, the base metal plate100 a may form the first surface layer 110 on one surface of the basemetal plate 100 a by a deposition process. Next, the second surfacelayer 120 may be formed on the other surface of the base metal plate 100a opposite to the one surface by the deposition process.

In addition, the first surface layer and the second surface layer may bedeposited together.

In addition, since the first surface layer 110 and the second surfacelayer 120 may be disposed on the base metal plate 100 a with a thicknesscorresponding to each other, an etch rate of a first surface 101 and asecond surface 102 of the base metal plate 100 a may be lowered.

A fifth step is a photoresist layer forming step in which a firstphotoresist layer P1 is disposed on the first surface layer 110 and asecond photoresist layer P2 is disposed on the second surface layer 120.Referring to FIG. 13, a first photoresist layer P1 having an open regionmay be disposed on the first surface layer 110, and a second photoresistlayer P2 having an open region may be disposed on the second surfacelayer 120. Specifically, a photoresist material is coated on each of thefirst surface layer 110 and the second surface layer 120, and the firstphotoresist layer P1 and the second photoresist layer P2 may be disposedby exposure and developing processes, respectively.

The first photoresist layer P1 and the second photoresist layer P2 aredisposed such that the widths of the open regions of the firstphotoresist layer P1 and the second photoresist layer P2 are differentfrom each other, so that the width of the first surface hole V1 formedon the first surface 101 and the second surface hole V2 formed on thesecond surface 102 may be different.

The first photoresist layer P1 and the second photoresist layer P2 mayinclude a plurality of open regions for forming through-holes in themetal plate.

A sixth step is a forming step of a through-hole in the metal plate.

The first photoresist layer P1 may be partially disposed on the firstsurface layer 110. Through-holes may not be formed in a region in whichthe first photoresist layer P1 is disposed on the first surface layer110. That is, the first photoresist layer P1 may include a substancecapable of maintaining physical/chemical stability in the etchingprocess. Accordingly, the first photoresist layer P1 may inhibit etchingof the first surface layer 110 and the base metal plate 100 a disposedunder the first photoresist layer P1.

The second photoresist layer P2 may be partially disposed on the secondsurface layer 120. Through-holes may not be formed in a region in whichthe second photoresist layer P2 is disposed on the second surface layer120. That is, the second photoresist layer P2 may include a substancecapable of maintaining physical/chemical stability in the etchingprocess. Accordingly, the second photoresist layer P2 may inhibitetching of the second surface layer 120 and the base metal plate 100 adisposed under the second photoresist layer P2.

Meanwhile, the open regions of the first photoresist layer P1 and thesecond photoresist layer P2 may be etched in the etching process.Accordingly, a through-hole of a metal plate may be formed in the openregions of the first photoresist layer P1 and the second photoresistlayer P2.

In addition, after a first photoresist for forming a first surface holeis formed and an etching preventive protection layer is formed on asecond surface, the first surface hole may be formed, and after aphotoresist for forming a second surface hole is formed and an etchingpreventive protection layer is formed on a first surface, the secondsurface hole may be formed.

Referring to FIG. 14, the first surface hole V1 is formed on a firstsurface of a metal plate by an etching process, the second surface holeV2 is formed on a second surface opposite to the first surface, and athrough-hole may be formed by the first surface hole V1 and the secondsurface hole V2 being communicated with each other by the connectingpart CA.

For example, the etching process may be performed by a wet etchingprocess. Accordingly, since the first surface 101 and the second surface102 may be simultaneously etched, process efficiency may be improved. Asan example, the wet etching process may be performed at about 45° C. byusing an etchant containing iron chloride. At this time, the etchant maycontain 35 to 45 wt % of FeCl3. Specifically, the etchant may contain 36wt % of FeCl3. For example, a specific gravity of the etchant containing43 wt % of FeCl3 may be 1.47 at 20° C. A specific gravity of the etchantcontaining 41 wt % of FeCl3 may be 1.44 at 20° C. A specific gravity ofthe etchant containing 38 wt % of FeCl3 may be 1.39 at 20° C. However,an embodiment is not limited thereto, and various etchants within arange in which an etch rate of a metal surface layer may be slower thanthat of a base metal plate may be used.

A seventh step is a removing step of the first photoresist layer and thesecond photoresist layer. Referring to FIG. 15, the first surface layer110 and the second surface layer 120 are disposed on the base metalplate 100 a by removing the first photoresist layer P1 and the secondphotoresist layer P2, and a metal plate having a plurality ofthrough-holes may be formed.

An etching factor of at least one surface hole of the first surface holeand the second surface hole calculated by the following Equation 1 inthe above process may be 2.5 or more. Accordingly, a through-hole of anembodiment may have excellent etching characteristics, and it ispossible to prevent a decrease in production yield due to lifting orseparation of a photoresist layer.

Etching Factor=B/A   Equation 1

In the equation, the B is a depth of one surface hole of the firstsurface hole and the second surface hole etched, and the A refers to awidth of the photoresist layer extending from a bridge region on the onesurface hole and protruding toward a center of the one surface hole.Specifically, the A refers to an average value of a width of one side ofthe photoresist layer protruding on the one surface hole and a width ofthe other side opposite to the one side.

Referring to FIG. 18, an etching step of forming one surface hole of thefirst surface hole and the second surface hole will be described.

In the above etching step, one surface hole of the first surface holeand the second surface hole may be formed in a region in which thephotoresist layer P is opened. At this time, since an etchant maycontact a lower portion of a side surface of a photoresist layerpositioned in the open region, undercutting may occur. Accordingly, aprotrusion portion of the photoresist layer may be positioned on the onesurface hole.

The protruding portion may be disposed on the surface hole while beingspaced apart from the surface hole. The protruding portion may surroundan end VE of the surface hole. The protruding portion may partiallycover the surface hole. The end PE of the protruding portion may bespaced apart from the end VE of the surface hole at a predetermineddistance. The end PE of the protruding portion may be disposed on thesurface hole. The protruding portion may not be in contact with thesurface hole. The protruding portion may be disposed on the surface holeby extending a photoresist layer in contact with the bridge region orthe outer region.

A shape of one of the first surface hole and the second surface hole maycorrespond to a shape of the open region of the photoresist layer. Forexample, when one of the first surface hole and the second surface holehas a circular shape, the open region of the photoresist layer may alsohave a circular shape.

An average diameter of one surface hole of the first surface hole andthe second surface hole may be larger than an average diameter of theopen region of the photoresist layer on the one surface hole. Forexample, the average diameter of the one surface hole of the firstsurface hole and the second surface hole may be 25 μm to 35 μm. Forexample, the average diameter of the open region of the photoresistlayer on the one surface hole may be 20 μm to 30 μm.

That is, a width of the open region of the photoresist layer and that ofthe through-hole may be different from each other. Specifically, a widthof one surface hole of the first surface hole and the second surfacehole formed under the open region of the photoresist layer may be largerthan that of the open region of the photoresist layer. Here, the widthof the one surface hole may refer to a maximum diameter measured on onesurface of the metal plate. Further, the width of the one surface holecompared with the width of the open region of the photoresist layer mayrefer to a width disposed at a position corresponding to “on” or“under”.

As a difference between the width of the open region of the photoresistlayer and the width of the one surface hole of the first surface holeand the second surface hole is smaller, etching characteristics may bebetter. Specifically, as the difference in width between the width ofthe open region of the photoresist layer and the width of the onesurface hole of the first surface hole and the second surface hole issmaller, a region in which undercutting occurs may be decreased.Accordingly, the convenience of designing through-holes may be improved,and fine through-holes may be formed efficiently in a process.

A ratio of the average diameter of the open region of the photoresistlayer and the average diameter of the surface hole may have a value of1:1.5 or less. For example, the ratio of the average diameter of theopen region of the photoresist layer and the average diameter of thesurface hole may have a value of 1:1.1 to 1:1.4. For example, the ratioof the average diameter of the open region of the photoresist layer andthe average diameter of the surface hole may have a value of 1:1.3 to1:1.4. When the ratio of the average diameter of the open region of thephotoresist layer and the average diameter of the surface hole exceeds1:1.5, etching characteristics may be deteriorated.

The value A of the Equation 1 may be expressed as Equation 2 below.

A=(A1+A2)/2   Equation 2

Referring to FIG. 18, the A1 in the Equation 2 may refer to a width ofone side of a protruding portion of a photoresist layer on the onesurface hole, A2 in the Equation 2 may refer to a width of the otherside opposite to the one side of the protruding portion of thephotoresist layer on the one surface hole.

That is, an etching factor of one of the first surface hole and thesecond surface hole may be redefined by Equation 3 below.

$\begin{matrix}{{EtchingFactor} = \frac{B}{\left\{ \frac{\left( {{A1} + {A2}} \right)}{2} \right\}}} & {{Equation}\mspace{14mu} 3}\end{matrix}$

A deposition mask according to an embodiment may be measured to have anetching factor of 2.5 or more in an etching step of forming athrough-hole. It may mean that as the etching factor is larger, theetching property is more excellent in a thickness direction of a metalplate, that is, in a depth direction of the through-hole.

It may mean that as the etching factor is smaller, a width of thethrough-hole becomes larger. That is, as the etching factor is smaller,the width of the through-hole becomes larger, so that a phenomenon ofwhich the photoresist layer is lifted or separated may occur.

At least one surface of the metal plate includes a surface hole, and thevalue A of the Equation 1 may be 8 or less. For example, the value A ofthe Equation 1 may be 5 or less. For example, the value A of theEquation 1 may be 4 to 5.

When the value A of the Equation 1 exceeds 8, the etching factor may bedecreased. When the value A of the Equation 1 is more than 8, adifference between the average diameter of the open region of thephotoresist layer and the average diameter of the one through-hole islarge, so that it is difficult to design fine through-holes.

Hereinafter, the present invention will be described in more detail withreference to exemplary embodiments and comparative examples. Such anembodiment is merely an example in order to explain the presentinvention in more detail. Therefore, the present invention is notlimited to such an embodiment.

Experimental Example 1: Size evaluation of average diameter of openregion of photoresist layer and average diameter of surface hole formedunder open region.

Exemplary Embodiment 1

A first surface layer and a second surface layer of a Ni—Cr alloymaterial were formed by deposition on a cold-rolled Invar base metalplate.

At this time, the Ni—Cr alloy was an alloy of 76 to 99 wt % of nickeland 1 to 24 wt % of chromium.

Thereafter, a photoresist layer including a plurality of open regionswas formed on one of the first surface layer and the second surfacelayer. Thereafter, an etching process was performed only on a surface inwhich the photoresist layer including a plurality of open regions wasformed.

In this manner, one surface hole of a first surface hole and a secondsurface hole was formed under the open region of the photoresist layer.

Exemplary Embodiment 2

A first surface layer and a second surface layer of a Ni—Cr—Fe alloymaterial were formed by deposition on a cold-rolled Invar base metalplate.

At this time, the Ni—Cr—Fe alloy was an alloy of 76 to 99 wt % of nickeland iron, and 1 to 24 wt % of chromium.

Thereafter, a photoresist layer including a plurality of open regionswas formed on one of the first surface layer and the second surfacelayer. Thereafter, an etching process was performed only on a surface inwhich the photoresist layer including a plurality of open regions wasformed.

In this manner, one surface hole of a first surface hole and a secondsurface hole was formed under the open region of the photoresist layer.In Exemplary Embodiment 2, thicknesses of respective layers andconditions of an etching process were the same except that the alloyformation of the surface layer of Exemplary Embodiment 2 was differentfrom that of Exemplary Embodiment 1.

COMPARATIVE EXAMPLE 1

A cold-rolled Invar base metal plate was prepared.

Thereafter, a photoresist layer including a plurality of open regionswas formed on one surface of the Invar base metal plate. Thereafter, anetching process was performed only on a surface in which the photoresistlayer including a plurality of open regions was formed.

In this manner, one surface hole of a first surface hole and a secondsurface hole was formed under the open region of the photoresist layer.

In Comparative Example 1, a thickness of the base metal plate was thesame as those in Exemplary Embodiments 1 and 2, and conditions of anetching process were also the same as those in Exemplary Embodiments 1and 2.

A difference between the average diameter of the open region of thephotoresist layer according to Exemplary Embodiments 1 and 2 and theaverage diameter of the surface hole formed under the open region wasmeasured to be smaller than a difference between the average diameter ofthe open region of the photoresist layer according to ComparativeExample 1 and the average diameter of the surface hole formed under theopen region.

The average diameter of the open region of the photoresist layer and theaverage diameter of the surface hole according to Exemplary Embodiments1 and 2 were measured to be 1:1.5 or less. Specifically, the averagediameter of the open region of the photoresist layer and the averagediameter of the surface hole according to Exemplary Embodiments 1 and 2were measured to be 1:1.1 to 1:1.4.

The average diameter of the open region of the photoresist layer and theaverage diameter of the surface hole according to Comparative Example 1were measured to be 1:1.7 or more. Specifically, the average diameter ofthe open region of the photoresist layer and the average diameter of thesurface hole according to Comparative Example 1 were measured to be1:1.7 to 1:1.8.

FIGS. 16 and 17 are photographs of surface holes formed by ExemplaryEmbodiment 1 and Comparative Example 1.

Referring to FIG. 16, a diameter of an open region of an arbitraryphotoresist layer formed according to Exemplary Embodiment 1 is 23.8 μm,and a diameter of an arbitrary surface hole disposed under the openregion of the photoresist layer is 32.85 μm.

Meanwhile, referring to FIG. 17, a diameter of an open region of anarbitrary photoresist layer formed according to Comparative Example 1 is22.43 μm, and a diameter of an arbitrary surface hole disposed under theopen region of the photoresist layer is 39.15 μm.

It was confirmed that the etching characteristics of the through-holewere excellent by satisfying the ratio of the average diameter of theopen region of the photoresist layer and the average diameter of thesurface hole according to Exemplary Embodiments 1 and 2 to 1:1.4 orless. In addition, it was confirmed that the deposition mask accordingto the embodiment may include through-holes with improved uniformity,and uniformity of a pattern shape deposited through the same isimproved.

EXPERIMENTAL EXAMPLE 2 Evaluation of Etching Factor

TABLE 1 Exemplary Exemplary Comparative Embodiment 1 Embodiment 2Example1 Etching factor 2.5 2.7 1.7

Table 1 shows etching factors according to Exemplary Embodiment 1,Exemplary Embodiment 2 and Comparative Example 1.

It can be seen that etching factors of deposition masks according toExemplary Embodiments 1 and 2 are 2.5 or more. For example, it can beseen that the etching factors of the deposition masks according toExemplary Embodiments 1 and 2 are 2.5 to 2.7. Accordingly, it can beseen that the deposition mask according to the embodiment may prevent aphotoresist layer from de-filming in an etching process, and etchingcharacteristics of a surface hole or through-holes is excellent.

On the other hand, it can be seen that an etching factor of a depositionmask according to Comparative Example 1 is less than 2.0. Specifically,it can be seen that the etching factor of the deposition mask accordingto Comparative Example 1 is 1.7. Accordingly, it can be seen that in thedeposition mask according to Comparative Example 1, de-filming of aphotoresist layer may occur in an etching process, and etchingcharacteristics of a surface hole or through-holes is deteriorated.

An etch rate refers to an amount etched per unit time.

A cold-rolled Invar base metal plate according to Comparative Example 1has an etch rate of an outer surface similar to that of an insidethereof. Even when a cold rolling process is performed, the outersurface and the inside thereof have the same compositions, and since acrystal structure of the outer surface and the inside thereof are thesame or similar, it can be seen that it is difficult to improve theetching characteristics only with the Invar material itself.

On the other hand, Exemplary Embodiments 1 and 2 may include first andsecond surface layers capable of improving the etching factor to 2.5 ormore. The metal surface layer of Exemplary Embodiment 1 is a binaryalloy containing chromium which may slow the etch rate than the basemetal plate. The metal surface layer of Exemplary Embodiment 2 is aternary alloy containing chromium which may slow the etch rate than thebase metal plate.

The metal surface layer according to Exemplary Embodiments 1 and 2 maycontain an element different from that of the base metal plate, as anexample, a metal element excellent in corrosion resistance such as Cr.Accordingly, it can be seen that the etch rate of the metal surfacelayer according to Exemplary Embodiments 1 and 2 is slower than that ofthe base metal plate. Accordingly, the metal plate according to theembodiment may form fine through-holes.

The etch rate of the surface layer may be slower than that of the basemetal plate. That is, the etch rate of the base metal plate may berelatively faster than that of the surface layer. That is, when etchinga base layer of the metal plate, the etch rate may be relatively slow ina side surface direction of the surface layer (direction A1, A2 in FIG.18), and the etch rate in a depth direction of the base metal plate(direction B in FIG. 18) may be relatively fast. Therefore, the etchfactor of the embodiment may be increased, and it is possible to formfine through-holes. The etch rate of the surface layer and the etch rateof the base metal plate may be confirmed by measuring an amount etchedper time while etching the metal plate. When the measurement isperformed in this manner, it can be confirmed that the etched amount isrelatively small at a time when the surface layer is etched and theetched amount is relatively large at a time when the base metal plate isetched.

FIG. 18 is a cross-sectional view of a surface hole according toExemplary Embodiment 1.

Referring to FIG. 18, when an etching factor is 2.5 or more, a width ofa surface hole may be small and the etching characteristics may beexcellent in a depth direction. In addition, when the etching factor is2.5 or more, a contact area of a bridge region BR positioned between aphotoresist layer and an adjacent through-hole may be large, therebystably preventing de-filming of the photoresist layer. Accordingly, itis possible to form a fine deposition pattern through the depositionmask according to the embodiment.

FIG. 19 is a cross-sectional view of a surface hole according toComparative Example 1.

Referring to FIG. 20, since a surface hole according to ComparativeExample 1 has an etching factor of 1.7, an adjacent through-hole may beoverlapped. Alternatively, a de-filming phenomenon of the photoresistlayer may occur. Accordingly, in Comparative Example 1, it can be seenthat the manufacturing yield and process efficiency of the through-holeare deteriorated.

A deposition mask according to an embodiment includes a metal plate, abase metal plate including a first surface and a second surface facingeach other, a first surface layer disposed on the first surface, and asecond surface layer disposed on the second surface, wherein the metalplate includes a plurality of through-holes, and an etching factor ofthe metal plate may be 2.5 or more.

In the deposition mask according to the embodiment, a metal surfacelayer may be disposed on the base metal plate before forming thethrough-hole. Accordingly, the surface layer may be opened without beingdisposed on a region in which the through-hole is disposed.

An inner region of the through-hole may include an element differentfrom that of the surface layer. In addition, although the inner regionof the through-hole includes the same element as that of the surfacelayer, composition of an included element may be different. Accordingly,an etch rate of the metal surface layer may be lowered.

That is, in the deposition mask according to the embodiment, the etchrate of the base metal plate may be faster than that of the metalsurface layer in an etching process for forming the through-hole, sothat etching efficiency may be improved and uniformity of thethrough-hole may be improved.

In addition, an OLED panel manufactured by the deposition mask accordingto the embodiment has excellent pattern deposition efficiency, and mayimprove deposition uniformity.

With reference to FIGS. 20 and 21, a deposition mask according to asecond embodiment will be described.

Features of the first and second embodiments may be combined and appliedexcept for a case which is inconsistent with a feature of the firstembodiment. A description overlapped with the first embodiment describedabove may be omitted. The same reference numerals may be assigned to thesame elements.

Referring to FIGS. 20 and 21, the metal plate included in the depositionmask according to the second embodiment may include a base metal plate100 a and a metal surface layer.

The metal surface layer may be disposed on one or both surfaces of thebase metal plate 100 a.

A first surface layer 110 may be disposed on one surface of the basemetal plate 100 a and a second surface layer 120 may be disposed on theother surface opposite to the one surface.

The metal plate for the deposition mask may include the first surfacelayer 110 and the second surface layer 120 on both surfaces of the basemetal plate 100 a. The base metal plate 100 a may be disposed in asandwich structure between the first surface layer 110 and the secondsurface layer 120.

The base metal plate 100 a may include a different material from that ofthe surface layer. The base metal plate 100 a may include a differentelement from that of the first surface layer 110. In addition, the basemetal plate 100 a may include a different element from that of thesecond surface layer 120.

In addition, the base metal plate 100 a may have a composition ratiodifferent from those of the first and second metal surface layers 110and 120.

In an embodiment, the first surface layer 110 and the second surfacelayer 120 include a different element from that of the base metal plate100 a, so that the corrosion rate of the first and second surface layersmay be slower than that of the base metal plate. That is, the corrosionrate of the base metal plate 100 a which is a bulk metal plate may befaster than the corrosion rate of the metal surface layer. Accordingly,the etching factor of the deposition mask according to the embodimentmay be increased. In addition, since the deposition mask according tothe embodiment may uniformly form a plurality of through-holes, thedeposition efficiency of R, G, and B patterns may be improved.

The surface layer may include various elements corresponding to primaryionization energy of 450 to 850 kj/mol such as Nb, V, In, Sb, etc., inaddition to metal elements such as Ni, Cr, Mo, Mn, Ti, Co, Cu, Fe, andAg.

The surface layer may include at least one element of Ni, Cr, Mo, Mn,Ti, Co, Cu, Fe, Au, Al, Mg, O, Ca, Cr, Si, Ti, Ag, Nb, V, In, and Sb.For example, the surface layer may be a binary layer including twodifferent elements of Ni, Cr, Mo, Mn, Ti, Co, Cu, Fe, Au, Al, Mg, O, Ca,Cr, Si, Ti, Ag, Nb, V, In, and Sb. For example, the surface layers 100 band 100 c may be a ternary layer including three different elements ofNi, Cr, Mo, Mn, Ti, Co, Cu, Fe, Au, Al, Mg, O, Ca, Cr, Si, Ti, Ag, In,and Sb. For example, the surface layer may be a layer including four ormore different elements of Ni, Cr, Mo, Mn, Ti, Co, Cu, Fe, Au, Al, Mg,O, Ca, Cr, Si, Ti, Ag, Nb, V, In, and Sb.

The surface layer may include at least one element of Al, Mg, O, Ca, Cr,Si, and Mn. As an example, the surface layer may be a metal oxide layer.At this time, the surface layer may be a surface layer formed by aseparate sputtering process or the like, which is not a natural oxidefilm which may be formed to 5 nm or less during transfer after a rollingprocess of the base metal plate. As an example, the surface layer may bea chromium layer or a chromium alloy layer. At this time, the chromiumcontent (wt %) of the surface layer may be larger than the chromiumcontent (wt %) of the base metal layer. The surface layer may delay thecorrosion rate on the surface of the metal plate used for the depositionmask. Accordingly, the deposition mask according to the embodiment mayimprove the etching factor.

A thickness of the base metal plate 100 a may be greater than athickness of the surface layer. The thickness of the base metal plate100 a may be greater than the thickness of at least one of the firstsurface layer 110 and the second surface layer 120.

The thickness of the base metal plate 100 a may be 30 μm or less. Forexample, the thickness of the base metal plate 100 a may be 1 μm to 30μm. For example, the thickness of the base metal plate 100 a may be 5 μmto 19.9 μm. For example, the thickness of the base metal plate 100 a maybe 15 μm to 19.5 μm. For example, the thickness of the base metal plate100 a may be 10 μm to 19.8 μm. When the thickness of the base metalplate 100 a exceeds 30 μm, a distance (pitch) between adjacentthrough-holes may be increased. Accordingly, efficiency of forming adisplay device with high definition or ultra high definition may bedeteriorated. Since the base metal plate of the embodiment may have athickness of 20 μm or less, the distance (pitch) between adjacentthrough-holes may be decreased. Therefore, it may be suitable to providea display device with high definition and/or ultra high definition. Thatis, the deposition mask according to the embodiment may increase pixelsper inch (PPI).

The first surface layer 110 and the second surface layer 120 may have athickness corresponding to each other. Here, the “corresponding” mayinclude an error due to tolerance.

The surface layer may be 0.5 nm to 1000 nm or less on one surface orboth surfaces of the base metal plate. The surface layer may be disposedat a thickness of 5 nm to 850 nm or less on the one surface or the bothsurfaces of the base metal plate. The surface layer may be disposed at athickness of 10 nm to 600 nm or less on the one surface or the bothsurfaces of the base metal plate.

The thickness of the first surface layer 110 may be 20 nm to 500 nm. Forexample, the thickness of the first surface layer 110 may be 20 nm to 50nm. For example, the thickness of the first surface layer 110 may be 25nm to 35 nm.

The thickness of the second surface layer 120 may be 20 nm to 500 nm.For example, the thickness of the second surface layer 120 may be 20 nmto 50 nm. For example, the thickness of the second surface layer 120 maybe 25 nm to 35 nm.

When the thickness of the surface layer is less than 1 nm, the effect ofimproving the etching factor by the metal surface layer may be reduced,and thus uniformity of the through-hole may be deteriorated. That is,when the thickness of the surface layer is less than 1 nm, athrough-hole having a large variation in thickness and/or width isformed, so that the pattern formed by the metal plate having thethrough-hole may not be uniform, and thus manufacturing efficiency ofthe display device may be deteriorated.

In addition, when the thickness of the surface layer is less than 1 nm,it may be difficult to form a through-hole having a fine size.

When the thickness of the surface layer exceeds 1 μm, manufacturingefficiency may be deteriorated. An interface between the base metalplate 100 a and the surface layer may include a cationic or anionicmaterial. The base metal plate 100 a may have a thin thickness of 20 μmor less by an acid etchant. Accordingly, the surface of the base metalplate 100 a may include a cation such as a proton (H₊) of an acidicsolution or an anion of a conjugate base by dissociation of an acidicsolution. As an example, the interface between the base metal plate 100a and the surface layer may include in 0.1 wt % or less any one ion ofCl—, HSO4-, H2PO4-, and CH3CO2- by dissociation of an acidic solutionsuch as hydrochloric acid, sulfuric acid, phosphoric acid, and aceticacid. However, since the acidic solution may be removed by washing withwater, substantially few cations such as proton (H₊) or anions of theconjugate base due to dissociation of the acidic solution may beremained. Here, substantially few remaining may mean that the cationsuch as proton (H₊) or the anion of the conjugate base due todissociation of the acidic solution is detected to be 0.01 wt % or less.

The base metal plate 100 a may include a surface etched with an acidicsolution. The base metal plate 100 a may have a larger roughness thanthe metal plate including the rolled surface. Specifically, the basemetal plate 100 a may have a greater arithmetic mean roughness (Ra) andten-point mean roughness (Rz) than the rolled Invar metal plate.

The arithmetic mean roughness (Ra) of the base metal plate 100 ameasured at the interface between the base metal plate and the surfacelayer may be more than 50 nm. For example, the arithmetic mean roughness(Ra) of the base metal plate 100 a measured at the interface between thebase metal plate and the surface layer may be 50 nm<Ra<300 nm. Forexample, the arithmetic mean roughness (Ra) of the base metal plate 100a measured at the interface between the base metal plate and the surfacelayer may be 50 nm<Ra<200 nm. For example, the arithmetic mean roughness(Ra) of the base metal plate 100 a measured at the interface between thebase metal plate and the surface layer may be 70 nm<Ra<150 nm.

The ten-point mean roughness (Rz) of the base metal plate 100 a measuredat the interface between the base metal plate and the surface layer maybe more than 800 nm. For example, the ten-point mean roughness (Rz) ofthe base metal plate 100 a measured at the interface between the basemetal plate and the surface layer may be 800 nm<Rz<2500 nm. For example,the ten-point mean roughness (Rz) of the base metal plate 100 a measuredat the interface between the base metal plate and the surface layer maybe 800 nm<Rz<2000 nm. For example, the ten-point mean roughness (Rz) ofthe base metal plate 100 a measured at the interface between the basemetal plate and the surface layer may be 800 nm<Rz<1500 nm.

The roughness of one surface of the first surface layer 110 which is indirect contact with the base metal plate 100 a may be larger than thatof the other surface opposite to the one surface of the first surfacelayer 110 forming the surface of the metal plate for the depositionmask. Accordingly, the interface between the base metal plate 100 a andthe first surface layer 110 may have excellent adhesion characteristics.In addition, since the roughness of the other surface of the firstsurface layer 110 forming the surface of the metal plate for thedeposition mask may be smaller than that of the one surface, etchingquality may be improved.

The roughness of one surface of the second surface layer 120 which is indirect contact with the base metal plate 100 a may be larger than thatof the other surface opposite to the one surface of the second surfacelayer 120 forming the surface of the metal plate for the depositionmask. Accordingly, the interface between the base metal plate 100 a andthe second surface layer 120 may have excellent adhesioncharacteristics. In addition, since the roughness the other surface ofthe second surface layer 120 forming the surface of the metal plate forthe deposition mask may be smaller than that of the one surface, etchingquality may be improved.

In addition, the base metal plate may form the through-hole and removethe surface layer. In this case, the arithmetic mean roughness (Ra)measured on the surface of the base metal plate from which the surfacelayer has been removed may be more than 50 nm.

The deposition mask 100 may have different widths of through-holes alongthe thickness direction of the through-hole.

Referring to FIG. 20, a width W1 of the first surface hole V1 may begreater than a width W3 of the connecting part CA. Specifically, thewidth of the through-hole may be reduced as the first surface hole V1goes from the first surface 101 toward the connecting part CA. Morespecifically, the width of the through-hole may be gradually reduced asthe first surface hole V1 goes from the first surface 101 toward theconnecting part CA.

A width W2 of the second surface hole V2 may be greater than the widthW3 of the connecting part CA. Specifically, the width of thethrough-hole may be reduced as the second surface hole V2 goes from thesecond surface 102 toward the connecting part CA. More specifically, thewidth of the through-hole may be gradually reduced as the second surfacehole V2 goes from the second surface 102 toward the connecting part CA.

Since a third surface hole V3 adjacent to the first surface hole V1 andformed on the first surface 101 communicates with a fourth surface holeV4 adjacent to the second surface hole V1 and formed on the secondsurface 102, through the connecting part CA, a through-hole may beformed.

A width W5 of the fourth through-hole V4 may be greater than a width W4of the third through-hole V3. For example, the width W4 of the thirdthrough-hole V3 may be greater than a width W6 of the connecting partCA. Specifically, the width of the through-hole may be reduced as thethird surface hole V3 goes from the first surface 101 toward theconnecting part CA. Specifically, the width of the through-hole may begradually reduced as the third surface hole V3 goes from the firstsurface 101 toward the connecting part CA. For example, the width W5 ofthe fourth surface hole V4 may be greater than the width W6 of theconnecting part CA. Specifically, the width of the through-hole may bereduced as the fourth surface hole V4 goes from the second surface 102toward the connecting part CA. More specifically, the width of thethrough-hole may be gradually reduced as the fourth surface hole V4 goesfrom the second surface 102 toward the connecting part CA.

Referring to FIG. 21, a width W1 of the first surface hole V1 may besmaller than a width W3 of the connecting part CA. Specifically, thewidth of the through-hole may be increased as the first surface hole V1goes from the first surface 101 toward the connecting part CA. Morespecifically, the width of the through-hole may be gradually increasedas the first surface hole V1 goes from the first surface 101 toward theconnecting part CA.

A width W2 of the second surface hole V2 may be greater than the widthW3 of the connecting part CA. Specifically, the width of thethrough-hole may be reduced as the second surface hole V2 goes from thesecond surface 102 toward the connecting part CA. More specifically, thewidth of the through-hole may be gradually reduced as the second surfacehole V2 goes from the second surface 102 toward the connecting part CA.

Since a third surface hole V3 adjacent to the first surface hole V1 andformed on the first surface 101 communicates with a fourth surface holeV4 adjacent to the second surface hole V1 and formed on the secondsurface 102, through the connecting part CA, a through-hole may beformed.

A width W5 of the fourth through-hole V4 may be greater than a width W4of the third through-hole V3. For example, the width W4 of the thirdthrough-hole V3 may be smaller than a width W6 of the connecting partCA. Specifically, the width of the through-hole may be increased as thethird surface hole V3 goes from the first surface 101 toward theconnecting part CA. Specifically, the width of the through-hole may begradually increased as the third surface hole V3 goes from the firstsurface 101 toward the connecting part CA. For example, the width W5 ofthe fourth surface hole V4 may be greater than the width W6 of theconnecting part CA. Specifically, the width of the through-hole may bereduced as the fourth surface hole V4 goes from the second surface 102toward the connecting part CA. More specifically, the width of thethrough-hole may be gradually reduced as the fourth surface hole V4 goesfrom the second surface 102 toward the connecting part CA. Accordingly,it is possible to efficiently form a deposition pattern having a finesize

Referring to FIGS. 21 and 22, a deposition mask according to anembodiment may include a plurality of through-holes. At this time, awidth of one through-hole may be 40 μm or less. For example, the widthof the through-hole may be 5 to 40 μm. For example, the width of thethrough-hole may be 10 to 35 μm. For example, at least one of the widthW1 of the first surface hole and the width W2 of the second surface holemay have a width of 40 μm or less. When the width of the through-hole ismore than 40 μm it may be difficult to form a fine deposition pattern.

Since a third surface hole V3 adjacent to the first surface hole V1 andformed on the first surface 101 communicates with a fourth surface holeV4 adjacent to the second surface hole V2 and formed on the secondsurface 102, through the connecting part CA respectively, a plurality ofthrough-holes may be formed.

A deposition mask according to an embodiment may include a bridge regionBR between an arbitrary first through-hole and a second through-holeadjacent to the first through-hole. For example, the first surface 101between the first surface hole V1 and the third surface hole V3 mayinclude a first bridge region BR1, and the second surface 102 betweenthe second surface hole V2 and the fourth surface hole V4 may include asecond bridge region BR2. The first bridge region BR1 may be larger thana plane area of the second bridge region BR2. The bridge region maysupport a plurality of through-holes to be spaced apart from each otherat a predetermined distance.

With reference to FIGS. 22 to 24, a deposition mask having varioussectional structures according to an embodiment will be described.

A deposition mask may include a first surface and a second surfacefacing each other, and may include an inflection point P2 between afirst surface hole V1 on the first surface and a second surface hole V2on the second surface.

With respect to the inflection point P2, an angle to the first surfacehole V1 and an angle to the second surface hole V2 may be different fromeach other. At this time, an inflection point may be an arbitrary pointat an end of a connecting part CA.

Referring to FIG. 22, an inclination angle θ1 of a deposition maskconnecting the inflection point P2 to an arbitrary point P3 of an end ofthe second surface hole V2 may be 90 degrees or less. When theinclination angle connecting the inflection point P2 to the arbitrarypoint P3 of the end of the second surface hole V2 exceeds 90 degrees, itmay be difficult to accommodate a deposition material, and thusdeposition efficiency may be deteriorated.

The inclination angle θ1 connecting the inflection point P2 to thearbitrary point P3 of the end of the second surface hole V2 may be inthe range of 20 to 70 degrees. When the inclination angle connecting theinflection point P2 to the arbitrary point P3 of the end of the secondsurface hole V2 is in the range of 20 to 70 degrees, uniformity of thedeposition may be improved.

For example, the inclination angle connecting the inflection point P2 tothe arbitrary point P3 of the end of the second surface hole V2 may bein the range of 30 to 60 degrees. For example, the inclination angleconnecting the inflection point P2 to the arbitrary point P3 of the endof the second surface hole V2 may be in the range of 32 to 38 degrees or52 to 58 degrees.

An inclination angle between an arbitrary point P1 of an end of thefirst surface hole V1 and an arbitrary point P3 of an end of the secondsurface hole V2 may be 70 degrees or less. For example, the inclinationangle between the arbitrary point P1 of the end of the first surfacehole V1 and the arbitrary point P3 of the end of the second surface holeV2 may be 60 degrees or less. For example, the inclination angle betweenthe arbitrary point P1 of the end of the first surface hole V1 and thearbitrary point P3 of the end of the second surface hole V2 may be 50degrees or less. Accordingly, it is possible to have an inclinationangle capable of accommodating a deposition material well.

An inclination angle θ2 of the deposition mask connecting the inflectionpoint P2 to the arbitrary point P1 of the end of the first surface holeV1 may be more than 90 degrees.

The inclination angle θ2 of the deposition mask connecting theinflection point P2 and the arbitrary point P1 at the end of the firstsurface hole V1 may be more than 90 degrees and 110 degrees or less.

In addition, the inclination angle θ2 of the deposition mask connectingthe inflection point P2 and the arbitrary point P1 at the end of thefirst surface hole V1 may be 95 degrees or more and 100 degrees or less.

That is, when the inclination angle θ2 of the deposition mask exceeds110 degrees, the first surface hole which has a larger width than theconnecting part may include a shadow region SA. Accordingly, aphenomenon of spreading of a deposition pattern released through thefirst surface hole may occur. When the inclination angle θ2 of thedeposition mask is less than 90 degrees, the deposition material may beseparated from the deposition substrate when the mask is removed afterdeposition through the mask.

In order to solve the problem that it is difficult to provide a displaydevice with high definition and/or ultra high definition by forming adeposition pattern greater than a width of a connecting region in thedeposition mask according to the embodiment, an entire thickness of themetal plate for the deposition mask may be formed to 20 μm or less. Inaddition, as a height H1 of the first surface hole is larger, thedeposition pattern spreads, so that the height H1 of the first surfacehole may be formed to 5 μm or less. For example, the height H1 of thefirst surface hole may be 3 μm or less. Meanwhile, a height H2 of thesecond surface hole V2 may be larger than the height H1 of the firstsurface hole V1. Further, in the embodiment, it is possible to form afine deposition pattern by forming a metal surface layer on the metalplate for the deposition mask and increasing an etching factor.

With reference to FIG. 23, easiness of forming a through-hole by forminga metal plate for a deposition mask to be 20 μm or less will bedescribed.

FIGS. 23(a), 23(b) and 23(c) are views explaining whether to form athrough-hole by etching when a thickness T of a metal plate for adeposition mask is changed.

When etching is performed for the same time by making a width of an openregion of a photoresist layer constant and using a metal plate of thesame material, it can be seen that a through-hole is not formed in FIGS.23(a) and 23(b) in which a thickness of the metal plate for thedeposition mask is large. On the other hand, it can be seen that thethrough-hole is formed in FIG. 23(c) in which the thickness of the metalplate for the deposition mask is small. That is, the metal plate for thedeposition mask according to the embodiment may have a thin thickness of20 μm or less, and the through-hole having a fine size may be formedquickly, so that a manufacturing process may be improved.

Referring to FIG. 24, easiness of forming a fine through-hole byincreasing an etching factor will be described.

FIGS. 24(a), 24(b), and 24(c) are views explaining whether to form athrough-hole by etching when a depth (b) in a center direction of anetched surface hole is changed. FIGS. 24(a), 24(b), and 24(c) are viewsshowing a change of an etching factor by making a width of an openregion of a photoresist layer constant and using a metal plate of thesame material.

FIG. 24(a) is view illustrating that the etching factor is 0.5 as awidth (a) of one end extending from a bridge region of an openedphotoresist layer and protruding toward a center of the surface hole andthe depth (b) in a center direction of an etched surface hole are in aratio of 1:0.5.

Etching Factor=B/A   Equation 1

In the Equation 1, the B is a depth in a center direction of an etchedsurface hole.

The A is a width of one end extending from a bridge region of an openedphotoresist layer and protruding toward a center direction of thesurface hole.

FIG. 24(b) is view illustrating that the etching factor is 1.0 as awidth (a) of one end extending from a bridge region of an openedphotoresist layer and protruding toward a center of the surface hole andthe depth (b) in a center direction of an etched surface hole are in aratio of 1:1.

FIG. 24(c) is view illustrating that the etching factor is 2.0 as awidth (a) of one end extending from a bridge region of an openedphotoresist layer and protruding toward a center of the surface hole andthe depth (b) in a center direction of an etched surface hole are in aratio of 1:2.

Referring to FIGS. 24(a), 24(b), and 24(c), it can be seen that a finesized through-hole is formed as an etching factor increases in a depthof the same metal plate. That is, a deposition mask for manufacturing adisplay device with high definition and/or ultra high definition shouldincrease the depth (b) in a center direction of an etched surface hole.To this end, the metal plate for the deposition mask according to anembodiment may include a metal surface layer on a base metal plate.

The etching factor of the deposition mask according to the embodimentmay be 1.2 or more. The etching factor of the deposition mask accordingto the embodiment may be 1.5 or more. The etching factor of thedeposition mask according to the embodiment may be 1.6 or more. Theetching factor of the deposition mask according to the embodiment may be2.0 or more. Accordingly, the deposition mask according to theembodiment may have a resolution of 600 PPI or more. For example, thedeposition mask according to the embodiment may have a resolution of 700PPI or more. For example, the deposition mask according to theembodiment may have a resolution of 800 PPI or more.

FIGS. 25 to 30 are views illustrating a manufacturing process of adeposition mask according to FIG. 22.

A deposition mask according to an embodiment may be manufactured byincluding: preparing a base metal plate; forming a surface layer todispose a metal surface layer on the base metal plate; forming aphotoresist layer to dispose a photoresist layer opened on the surfacelayer; and etching to form a surface hole at a position corresponding tothe opened photoresist layer.

First, with reference to FIG. 25, a preparing step of a metal substratewill be described. A metal substrate MS may include a metal material.The metal substrate MS may include a nickel alloy. For example, themetal substrate MS may be an alloy of nickel and iron. At this point,the nickel may be about 35 to 37 wt %, and the iron may be about 63 to65 wt %. For example, the metal substrate MS may include Invar includingabout 35 to 37 wt % of nickel, about 63 to 65 wt % of iron, and at leastone of a trace amount of C, Si, S, P, Cr, Mo, Mn, Ti, Co, Cu, Fe, Ag,Nb, V, In, and Sb.

A thickness To of the metal substrate MS may be more than 20 μm. Forexample, the thickness To of the metal substrate MS may be 30 μm orless. Specifically, the thickness To of the metal substrate MS may be 25μm or less. Accordingly, a thickness of the base metal plate 100 a maybe manufactured to be 20 μm or less.

Alternatively, the thickness To of the metal substrate MS may be 20 μmor less. Accordingly, the thickness of the base metal plate 100 a may bemanufactured to be 15 μm or less.

The preparing step of the base metal plate may include various thicknessreduction steps. For example, the base metal plate may further include athickness reduction step by chemical or electrical treatment. That is,the preparing step of the base metal plate may include treating themetal substrate MS having a thickness of more than 20 μm to a base metalplate having a thickness of 20 μm or less.

With reference to FIG. 26, a forming step of a base metal plate will bedescribed.

Since the metal substrate MS is treated by a chemical or electricalmethod, a thickness of the base metal plate may be decreased by a rangeof about 15% to about 25% compared with that of the metal substrate MS.

Since the metal substrate MS is etched by a chemical agent, a base metalplate 100 a having a thickness decreased by about 20% compared with thatof the metal substrate MS may be formed. At this time, the chemicalagent is an acidic solution, and may be various organic acid solutionsor various inorganic acid solutions. Alternatively, since the metalsubstrate MS is electrically electrolyzed, a base metal plate 100 ahaving a thickness decreased by about 20% compared with that of themetal substrate MS may be formed.

That is, the base metal plate 100 a according to an embodiment may bemanufactured without using a rolling method. In order to manufacture adisplay device with ultra high definition, an Invar having a thicknessof 20 μm or less should be provided. A thick raw material may beprocessed into a thin Invar by a repetitive rolling process, but thereis a problem that the process difficulty is high and the process cost ishigh. In order to solve such a problem, the Invar may be processed intoa thin thickness by the chemical or electrical method. Accordingly, athickness T1 of a non-rolled base metal plate 100 a may be 20 μm orless. For example, the thickness T1 of the non-rolled base metal plate100 a may be 15 μm or less.

With reference to FIG. 27, a forming step of a metal surface layer willbe described.

Since a surface of the base metal plate 100 a is processed by thechemical or electrical treatment, an etching factor is deteriorated.That is, the surface of the base metal plate 100 a is deformed so as tohave a large roughness by chemical or electrical treatment, so that theetching factor may be deteriorated.

Accordingly, a metal surface layer may be formed on one or both surfacesof the base metal plate 100 a. For example, when a first surface holeand a second surface hole are formed by double-sided etching of a metalplate, a first surface layer 110 and a second surface layer 120 may beformed on the both surfaces of the base metal plate 100 a.

Alternatively, as shown in FIG. 32, when only a second surface hole isformed by etching of one surface of the metal plate, a metal surfacelayer may be formed on one surface of the base metal plate 100 a.

The surface layer may be various materials capable of improving anetching factor. The surface layer may be various materials for providingan etching factor of 1.2 or more. The surface layer may be variousmaterials for providing an etching factor of 1.5 or more. The surfacelayer may be various materials for providing an etching factor of 1.6 ormore. The surface layer may be various materials for providing anetching factor of 2.0 or more.

The surface layer may be formed to be 1 μm or less. The surface layermay be formed to be 100 nm or less. The surface layer may be formed tobe 50 nm or less. The surface layer may include at least one element ofAl, Mg, O, Ca, Cr, Si, and Mn.

A thickness T2 of the first surface layer 110 may be 1 nm to 100 nm. Thethickness T2 of the first surface layer 110 may be 1 nm to 50 nm.

A thickness T3 of the second surface layer 120 may be 1 nm to 100 nm.The thickness T3 of the second surface layer 120 may be 1 nm to 50 nm.

That is, an adhesion force of the surface layer to the photoresist layermay be different depending on a contained element, and the etchingfactor may be different. Therefore, it may have various optimumthicknesses in a range of 1 nm to 100 nm depending on the elementcontained in the metal surface layer.

The surface layer may be formed by various methods such as deposition,electroplating, a solution process and the like. For example, thesurface layer may be formed in a deposition process to form a thin filmshape. Alternatively, the surface layer may be formed by plating inorder to be manufactured thicker than the deposition process.Alternatively, the surface layer may be formed by treating with asolution containing nano or micro particles. In addition, the surfacelayer may oxidize the base metal plate to increase the etching factor.

With reference to FIG. 28, a forming step of a photoresist layer will bedescribed.

A first photoresist layer P1 may be disposed on the first surface layer110, and a second photoresist layer P2 may be disposed on the secondsurface layer 120.

The first photoresist layer P1 having an open region may be disposed onthe first surface layer 110, and the second photoresist layer P2 havingan open region may be disposed on the second surface layer 120.Specifically, a photoresist material is coated on each of the firstsurface layer 110 and the second surface layer 120, and the firstphotoresist layer P1 and the second photoresist layer P2 may be disposedby exposure and developing processes, respectively.

The first photoresist layer P1 and the second photoresist layer P2 aredisposed such that the widths of the open regions of the firstphotoresist layer P1 and the second photoresist layer P2 are differentfrom each other, so that the width of the first surface hole V1 formedon the first surface 101 and the second surface hole V2 formed on thesecond surface hole 102 may be different.

The first photoresist layer P1 and the second photoresist layer P2 mayinclude a plurality of open regions for simultaneously formingthrough-holes in a metal plate for a deposition mask.

With reference to FIG. 29, an etching step for forming a surface holewill be described.

The first photoresist layer P1 may be partially disposed on the firstsurface layer 110. Through-holes may not be formed in a region in whichthe first photoresist layer P1 is disposed on the first surface layer110. That is, the first photoresist layer P1 may include a substancecapable of maintaining physical/chemical stability in the etchingprocess. Accordingly, the first photoresist layer P1 may inhibit etchingof the first surface layer 110 and the base metal plate 100 a disposedunder the first photoresist layer P1.

The second photoresist layer P2 may be partially disposed on the secondsurface layer 120. Through-holes may not be formed in a region in whichthe second photoresist layer P2 is disposed on the second surface layer120. That is, the second photoresist layer P2 may include a substancecapable of maintaining physical/chemical stability in the etchingprocess. Accordingly, the second photoresist layer P2 may inhibitetching of the second surface layer 120 and the base metal plate 100 adisposed under the second photoresist layer P2.

Meanwhile, the open regions of the first photoresist layer P1 and thesecond photoresist layer P2 may be etched in the etching process.Accordingly, a through-hole of a metal plate may be formed in the openregions of the first photoresist layer P1 and the second photoresistlayer P2.

The first surface hole V1 is formed on a first surface of a metal plateby an etching process, the second surface hole V2 is formed on a secondsurface opposite to the first surface, and a through-hole may be formedby the first surface hole V1 and the second surface hole V2 beingcommunicated with each other by a connecting part CA.

For example, the etching process may be performed by a wet etchingprocess. Accordingly, since the first surface 101 and the second surface102 may be simultaneously etched, process efficiency may be improved. Asan example, the wet etching process may be performed at about 45° C. byusing an etchant containing iron chloride. At this time, the etchant maycontain 35 to 45 wt % of FeCl3. Specifically, the etchant may contain 36wt % of FeCl3. For example, a specific gravity of the etchant containing43 wt % of FeCl3 may be 1.47 at 20° C. A specific gravity of the etchantcontaining 41 wt % of FeCl3 may be 1.44 at 20° C. However, an embodimentis not limited thereto, and various etchants may be used.

In the metal plate of a deposition mask, in order to form a through holepassing through the first surface layer 110, the base metal plate 100 a,and the second surface layer 120, an etchant may be in contact with alower surface of the first surface layer 110 and an upper surface of thesecond surface layer 120. At this time, the first surface layer 110 andthe second surface layer 120 may contain a material that is moreresistant to the etchant compared with that of the base metal plate 100a, so that an etching factor may be improved.

With reference to FIG. 30, a forming step of a deposition mask byremoving a photoresist layer will be described. The first surface layer110 and the second surface layer 120 are disposed on the base metalplate 100 a by removing the first photoresist layer P1 and the secondphotoresist layer P2, and a metal plate having a plurality ofthrough-holes may be formed.

An etching factor of at least one surface of the first surface hole andthe second surface hole calculated by the following equation 1 after theetching step, may be 1.2 or more. The etching factor of at least onesurface of the first surface hole and the second surface hole calculatedby the following equation 1 may be 1.5 or more. The etching factor of atleast one surface of the first surface hole and the second surface holecalculated by the following equation 1 may be 1.6 or more. The etchingfactor of at least one surface of the first surface hole and the secondsurface hole calculated by the following equation 1 may be 2.0 or more.

An etching factor of a first surface hole and a second surface hole of adeposition mask may be 1.2 or more. The etching factor of the firstsurface hole and the second surface hole of the deposition mask may be1.5 or more. The etching factor of the first surface hole and the secondsurface hole of the deposition mask may be 1.6 or more. The etchingfactor of the first surface hole and the second surface hole of thedeposition mask may be 2.0 or more.

Preferably, the etching factor of the second surface hole larger thanthe first surface hole may be 1.2 or more. The etching factor of thesecond surface hole larger than the first surface hole may be 1.5 ormore. The etching factor of the second surface hole may be 1.6 or more.The etching factor of the second surface hole may be 2.0 or more.

Etching Factor=B/A   Equation 1

In the equation 1, the B is a depth in a center direction of an etchedsurface hole.

The A is a width of one end extending from a bridge region of an openedphotoresist layer and protruding toward a center of the surface hole.

In addition, a deposition mask according to an embodiment may have athickness of 20 μm or less. Accordingly, the deposition mask accordingto the embodiment may provide a display device with high definition andultra high definition.

The deposition mask according to the embodiment may have variousstructures.

The inclination angle of the first surface hole according to theembodiment may be variable.

Referring to FIG. 31, an inclination angle θ1 of a deposition maskconnecting the inflection point P2 to an arbitrary point P3 of an end ofthe second surface hole V2 may be 90 degrees or less. When theinclination angle connecting the inflection point P2 to the arbitrarypoint P3 of the end of the second surface hole V2 exceeds 90 degrees, itmay be difficult to accommodate a deposition material, and thusdeposition efficiency may be deteriorated.

The inclination angle θ1 connecting the inflection point P2 to thearbitrary point P3 of the end of the second surface hole V2 may be inthe range of 20 to 70 degrees. When the inclination angle connecting theinflection point P2 to the arbitrary point P3 of the end of the secondsurface hole V2 is in the range of 20 to 70 degrees, uniformity of thedeposition may be improved.

For example, the inclination angle connecting the inflection point P2 tothe arbitrary point P3 of the end of the second surface hole V2 may bein the range of 30 to 60 degrees. For example, the inclination angleconnecting the inflection point P2 to the arbitrary point P3 of the endof the second surface hole V2 may be in the range of 32 to 38 degrees or52 to 58 degrees.

An inclination angle between an arbitrary point P1 of an end of thefirst surface hole V1 and an arbitrary point P3 of an end of the secondsurface hole V2 may be 70 degrees or less. For example, the inclinationangle between the arbitrary point P1 of the end of the first surfacehole V1 and the arbitrary point P3 of the end of the second surface holeV2 may be 60 degrees or less. For example, the inclination angle betweenthe arbitrary point P1 of then end of the first surface hole V1 and thearbitrary point P3 of the end of the second surface hole V2 may be 50degrees or less. Accordingly, it is possible to have an inclinationangle capable of accommodating a deposition material well.

An inclination angle θ2 of a deposition mask connecting the inflectionpoint P2 to an arbitrary point P1 of an end of the first surface hole V1may be 90 degrees or less. That is, a width of the connecting part isgreater than a width of the first surface hole, and thus the shadowregion SA may not be included.

This may be different according to a deposition method. In the case ofFIG. 22, a deposition angle from a deposition source material fordeposition at the time of deposition to the point P1 is large, and thusit is easy when a deposition material may be attached to the point P1,and in the case of the embodiment of FIG. 31, a deposition sourcematerial has a low adhesion force to a metal substrate, and thus it iseasy when the deposition material is not attached to the metal substrateat the point P1.

An angle to the inflection point with respect to the second surface andan angle to the first surface hole with respect to the inflection pointmay be 90 degrees or less, respectively. At this time, the angle to theinflection point with respect to the second surface may be smaller thanthe angle to the first surface hole with respect to the inflectionpoint. That is, the inclination angle θ2 of a deposition mask connectingthe inflection point P2 to the arbitrary point P1 of the end of thefirst surface hole V1 is greater than the inclination angle θ1connecting the inflection point P2 to an arbitrary point P3 of an end ofthe second surface hole V2.

As an example, the metal surface layer may include at least one elementselected from Ni, Cr, Fe, Au, Mo, O and Ti. For example, in the metalplate of the deposition mask according to the embodiment, the etch rateon the surface may be decreased by forming a Cr-containing surface layeron an Invar metal plate or forming an O-containing surface layer, sothat the inclination angle between the inflection point and the firstsurface hole may be formed to 90 degrees or less.

A width of the second surface hole may be greater than a width of theinflection point and the width of the inflection point may be greaterthan the width of the first surface hole. Alternatively, the width ofthe second surface hole may be greater than the width of the inflectionpoint, and the width of the inflection point may correspond to the widthof the first surface hole. For example, the width of the first surfacehole and the width of the inflection point may be in a ratio of 0.5:1 to1:1.

Accordingly, it is possible to prevent a phenomenon of spreading of adeposition pattern released through the first surface hole.

The deposition mask according to the embodiment may provide a displaydevice with high definition and/or ultra high definition bycorresponding the width of the connecting part to the width of thedeposition pattern or forming the width of the connecting part to begreater than that of the deposition pattern. The deposition maskaccording to the embodiment may have a resolution of 800 PPI or more.

The embodiment may not include the first surface hole.

Referring to FIG. 32, a second surface layer 120 may be included only onone surface of the base metal plate 100 a when etching is performed onlyon one surface of a metal plate for a deposition mask. Accordingly, inan embodiment, it is possible to form a through-hole including only asecond surface hole. The second surface hole may be in a shape capableof accommodating a deposition material and an organic material may bedeposited in a width corresponding to an end of the second surface hole,and thus it is possible to prevent a diffusion phenomenon of thedeposition material depending on a thickness of a first surface hole.Accordingly, the deposition mask according to the embodiment may improvedeposition efficiency.

Therefore, the deposition mask according to the embodiment maymanufacture a display device with high definition.

Hereinafter, the present invention will be explained in more detailthrough Exemplary Embodiments and Comparative Examples. Such anembodiment is merely presented as an example to explain the presentinvention in more detail. Therefore, the present invention is notlimited to such an embodiment.

In Comparative Example 1, a photoresist layer was disposed on a 30 μmmetal plate for a base deposition mask, and a through-hole was formed bywet etching.

In Comparative Example 2, a photoresist layer was disposed on a basemetal plate thinned to a thickness of 20 μm or less by etching the 30 μmmetal plate for the base deposition mask of Comparative Example 1, and athrough-hole was formed by wet etching.

In Exemplary Embodiment 1, a Ni metal surface layer was formed on thebase metal plate of Comparative Example 2. A photoresist layer wasdisposed on the metal surface layer containing Ni, and a through-holewas formed by wet etching.

In Exemplary Embodiment 2, a Cr and Ni metal surface layer was formed onthe base metal plate of Comparative Example 2. A photoresist layer wasdisposed on a metal surface layer containing a binary alloy of Cr andNi, and a through-hole was formed by wet etching.

In Exemplary Embodiment 3, a Fe and Ni metal surface layer was formed onthe base metal plate of Comparative Example 2. A photoresist layer wasdisposed on a metal surface layer containing a binary alloy of Fe andNi, and a through-hole was formed by wet etching.

As described above, the surface layer may be removed after forming athrough-hole by wet etching.

An etching factor was measured under the same conditions for a width ofthe open region of the photoresist layer of Comparative Examples andExemplary Embodiments, a temperature of an etchant and a type of theetchant.

Experimental Example 1: Evaluation of adhesion force of photoresistlayer, etching factor, and through-hole quality.

TABLE 2 Exemplary Exemplary Exemplary Comparative Comparative EmbodimentEmbodiment Embodiment Example 1 Example 2 1 2 3 Adhesion force of ◯ ◯ ◯◯ ◯ photoresist layer Etching factor 1.0 1.15 3.0 3.2 2.8 Through-hole XX ◯ ◯ ◯ quality

Table 2 shows evaluation results of an adhesion force of a photoresistlayer, an etching factor and through hole quality of ExemplaryEmbodiments and Comparative Examples.

When de-filming of the photoresist layer does not occur, it wasindicated by

When a size deviation between the maximum value and the minimum value ofdiameters of through-holes is within ±3 μm, it was indicated by

Specifically, when a size deviation of holes adjacent to a referencehole is within ±3 μm, it was indicated by

Referring to Table 2, it is confirmed that the metal surface layers ofExemplary Embodiments 1 to 3 include at least one element selected fromNi, Cr and Fe, thereby improving an etching factor to 1.2 or more. Itcan be confirmed that the etching factor of the metal surface layers inExemplary Embodiments 1 to 3 is improved to 1.5 or more. It can beconfirmed that the etching factor of the metal surface layers inExemplary Embodiments 1 to 3 is improved to 1.6 or more. It can beconfirmed that the etching factor of the metal surface layers inExemplary Embodiments 1 to 3 is improved to 2.0 or more. It can beconfirmed that the etching factor of the metal surface layers ofExemplary Embodiments 1 to 3 is increased to 2.8 or more by including anickel layer or a binary alloy containing nickel. Accordingly, thedeposition mask according to the embodiment may reduce a distance(pitch) of through-holes. In addition, the deposition mask according tothe embodiment may form a fine sized through-hole to have excellentquality, and an OLED panel with ultra high definition may bemanufactured through the same.

The characteristics, structures, effects, and the like described in theabove-described embodiments are included in at least one embodiment ofthe present invention, but are not limited to only one embodiment.Furthermore, the characteristic, structure, and effect illustrated ineach embodiment may be combined or modified for other embodiments by aperson skilled in the art. Accordingly, it is to be understood that suchcombination and modification are included in the scope of the presentinvention.

The above description of the embodiments is merely examples and does notlimit the present invention. It would be apparent to those of ordinaryskill in the art that the present invention may be easily embodied inmany different forms without changing the technical idea or essentialfeatures thereof. For example, elements of the exemplary embodimentsdescribed herein may be modified and realized. Also, it should beconstrued that differences related to such changes and applications areincluded in the scope of the present invention defined in the appendedclaims.

What is claimed is:
 1. A deposition mask comprising; a metal platecomprising iron (Fe) and nickel (Ni), wherein the metal plate extends ina longitudinal direction of the metal plate from a first end to a secondend, wherein the metal plate includes a first surface and a secondsurface opposite to the first surface, wherein the metal plate includesa deposition pattern region and a non-deposition region, wherein thedeposition pattern region includes a plurality of effective regions anda plurality of ineffective regions, wherein part of the ineffectiveregions is disposed between different ones of the effective regions,wherein each of the effective regions includes a plurality ofthrough-holes, wherein the metal plate includes a first groove, a secondgroove, a third groove, and a fourth groove, wherein the first groove,the second groove, the third groove, and the fourth groove are separateregions in which a corresponding groove is formed in a depth directionof the metal plate, wherein the first groove and the second groove aredisposed in the non-deposition region, wherein the third groove isdisposed between any one of adjacent effective regions, wherein thefourth groove is disposed between other one of the adjacent effectiveregions.
 2. The deposition mask according to claim 1, wherein the firstgroove is disposed between the first end of the metal plate and a firstside surface of the deposition pattern region, wherein the second grooveis disposed between the second end of the metal plate and a second sidesurface of the deposition pattern region opposite to the first side. 3.The deposition mask according to claim 1, wherein the first groove has acurved surface and a flat surface, and the second groove has a curvedsurface and a flat surface.
 4. The deposition mask according to claim 3,wherein the flat surface of the first groove is aligned in a widthdirection of the metal plate, and the flat surface of the second grooveis aligned in the width direction of the metal plate, wherein the curvedsurface of the first groove has a convex shape toward the first end ofthe metal plate, and the curved surface of the second groove has aconvex shape toward the second end of the metal plate.
 5. The depositionmask according to claim 1, wherein a shape of the third groove isdifferent from a shape of either one of the first and second grooves,and a shape of the fourth groove is different from a shape of either oneof the first and second grooves.
 6. The deposition mask according toclaim 1, wherein the third groove and the fourth groove each separatelyhave a rectangular shape, wherein the first groove, the second groove,the third groove, and the fourth groove each separately extend in adepth direction of the metal plate to a half depth of the metal plate.7. The deposition mask according to claim 1, wherein the first groove,the second groove, the third groove and the fourth groove are formed onat least one of the first surface or the second surface of the metalplate. wherein the plurality of through-holes includes a first surfacehole on the first surface of the metal plate and a second surface holeon the second surface of the metal plate, wherein a width of the secondsurface hole on the second surface is greater than a width of the firstsurface hole on the first surface.
 8. The deposition mask according toclaim 6, wherein the first groove, the second groove, the third grooveand the fourth groove are provided only on the first surface of themetal plate.
 9. The deposition mask according to claim 1, wherein afirst width of the first groove is a maximum width of the longitudinaldirection of the first groove, a second width of the third groove is amaximum width the longitudinal direction of the third groove, and thefirst width of the first groove is greater than the second width of thethird groove.
 10. The deposition mask according to claim 1, wherein themetal plate has a first open portion at the first end of the metal plateand a second open portion at the second end of the metal plate.
 11. Thedeposition mask according to claim 10, wherein a length of the firstgroove in the width direction of the metal plate is 95% to 110% of alength of the first open portion in the width direction of the metalplate, and a length of the second groove in the width direction of themetal plate is 95% to 110% of a length of the second open portion in thewidth direction of the metal plate.
 12. A deposition mask, comprising: ametal plate that includes iron (Fe) and nickel (Ni), wherein the metalplate extends in a longitudinal direction of the metal plate from afirst end to a second end, wherein the metal plate includes a firstsurface and a second surface opposite to the first surface, wherein themetal plate includes a deposition pattern region and a non-depositionregion, wherein the deposition pattern region includes a plurality ofeffective regions and a plurality of ineffective regions, wherein partof the ineffective regions is disposed between different ones of theeffective regions, wherein each of the effective regions includes aplurality of through-holes, wherein the metal plate includes a firstgroove, a second groove, a third groove, and a fourth groove, whereinthe first groove, the second groove, the third groove, and the fourthgroove are separate regions in which a corresponding groove is formed ina depth direction of the metal plate, wherein the first groove isdisposed between the first end of the metal plate and a first side ofthe deposition pattern region, and the second groove is disposed betweenthe second end of the metal plate and a second side of the depositionpattern region opposite to the first side, wherein the third groove isdisposed between the first groove and an effective area closest to thefirst groove, wherein the fourth groove is disposed between the secondgroove and an effective area closest to the second groove.
 13. Thedeposition mask according to claim 12, wherein a shape of the thirdgroove is different from a shape of either one of the first and secondgrooves, and a shape of the fourth groove is different from a shape ofeither one of the first and second grooves.
 14. The deposition maskaccording to claim 12, wherein the third groove and the fourth grooveeach separately have a rectangular shape, wherein the first groove, thesecond groove, the third groove, and the fourth groove each separatelyextend in a depth direction of the metal plate to a half depth of themetal plate.
 15. The deposition mask according to claim 12, wherein thefirst groove, the second groove, the third groove and the fourth grooveare formed on at least one of the first surface or the second surface ofthe metal plate. wherein the plurality of through-holes includes a firstsurface hole on the first surface of the metal plate and a secondsurface hole on the second surface of the metal plate, wherein a widthof the second surface hole on the second surface is greater than a widthof the first surface hole on the first surface.
 16. The deposition maskaccording to claim 12, wherein a first width of the first groove is amaximum width of the longitudinal direction of the first groove, asecond width of the third groove is a maximum width the longitudinaldirection of the third groove, and the first width of the first grooveis greater than the second width of the third groove.
 17. The depositionmask according to claim 11, wherein the first groove, the second groove,the third groove and the fourth groove are provided only on the firstsurface of the metal plate.
 18. The deposition mask according to claim12, wherein the metal plate has a first open portion at the first end ofthe metal plate and a second open portion at the second end of the metalplate.
 19. The deposition mask according to claim 18, wherein a lengthof the first groove in the width direction of the metal plate is 95% to110% of a length of the first open portion in the width direction of themetal plate, and a length of the second groove in the width direction ofthe metal plate is 95% to 110% of a length of the second open portion inthe width direction of the metal plate.